Givaudan-Roure Lecture - Association for Chemoreception Sciences

1 Givaudan-Roure Lecture [ ] Givaudan-Roure Lecture 

WHY NEW NEURONS IN THE ADULT OLFACTORY BULB 

Alvarez-Buylla A. 1 1Department of Neurological Surgery and Program 

in Developmental and Stem Cell Biology, University of California at 

San Francisco, San Francisco, CA 

New neurons continue to be formed in adult brains. These cells 

incorporate into mature circuitry raising questions on how these cells 

are formed and what is their functional contribution. Adult 

neurogenesis is most prominent in the subventricular zone (SVZ) on the 

lateral walls of the lateral ventricles. This process has now been 

described in many species including primates. Young neurons born in 

the SVZ engage in an extraordinary journey, along the walls of the 

lateral ventricle and the rostral migratory stream that leads into the 

olfactory bulb, where these cells differentiate into granule and 

periglomerular interneurons. These cells must be continually replaced 

in adult life, as their total number remains unchanged in adults. I will 

review recent advances on the origin, mechanism of migration and 

integration of these new neurons in adult brain. I will describe the 

different stages in the maturation and present electrophysiological 

evidence demonstrating that these neurons become functionally 

incorporated in adult olfactory bulb circuits. Surprisingly, soon after 

full maturation and incorporation many of the new neurons die in a 

process that appears to be dependent on olfactory activity. A computer 

model of a neural network that approximates the circuitry of the 

olfactory bulb predicts that replacement of neurons through an activitydependent 

mechanism greatly improves odor discrimination. A 

similar principle could apply to other circuits that receive new neuron in 

adults. 

2 Slide [ ] Olfactory Bulb Physiology 

UNDERSTANDING THE ROLE OF GAP JUNCTIONS IN 

OLFACTORY FUNCTION 

Zhang C. 1, Restrepo D. 1 1Department of Cellular and Developmental 

Biology, Neuroscience Program and the Rocky Mountain Smell and 

Taste Center, University of Colorado Health Sciences Center, Denver, 

CO 

Previously, we reported that we had generated OlfDNCX mice that 

express a dominant negative connexin 43 protein (Cx43/&beta-gal) in 

mature olfactory receptor neurons (ORNs) to inactivate Cx43 gap 

junctions (Chem. Sense 27:664). The use of olfactory marker protein 

promoter to drive the expression of Cx43/&beta-gal ensures the 

dysfunction of gap junctions occurs only in mature ORNs, without 

affecting the function of gap junctions in other epithelial cells and the 

maturation of olfactory epithelial cells. Using electro-olfactogram 

(EOG) recordings, we found that 500 &muM IBMX, a 

phosphodiesterase inhibitor that elicits responses by increasing 

intracellular cAMP, consistently induced large olfactory responses in 

various location in the olfactory epithelium and that the magnitude did 

not differ between OlfDNCX and controls. This suggests that 

Cx43/&beta-gal expression in the olfactory epithelium in OlfDNCX did 

not result in a gross interference of signal transduction machinery in 

ORNs. We decided to conduct a systematic study to understand how 

dysfunction of gap junctions in mature ORNs will affect responses to 

odors at the peripheral level, odor maps in the olfactory bulb and 

olfactory sensation. We found that OlfDNCX had reduced EOG 

responses to select odors, including octaldehyde, which led to “simpler” 

odor maps in the olfactory bulb as compared to controls. Gap junctions 

in the olfactory epithelium are likely to play a role in odor detection and 

discrimination. 

This work was supported by grants DC04952, DC00566 and 

DC04657 from the NIDCD. 

1 


REAL-TIME IMAGING OF ODORANT-STIMULATED NITRIC 

OXIDE PRODUCTION IN THE ANTENNAL LOBE OF 

MANDUCA SEXTA 

Nighorn A. 1, Carlsson M. 2, Hansson B. 3, Collmann C. 1 1Neurobiology, 

University of Arizona, Tucson, AZ; 2Swedish Agricultural University, 

Alnarp, Sweden; 3Swedish University of Agricultural Sciences, Alnarp, 

Sweden 

In the antennal lobe (AL) of the moth, Manduca sexta, nitric oxide 

synthase is expressed exclusively in the axons of most or all olfactory 

receptor neurons (ORNs), and soluble guanylyl cyclase is expressed in 

subsets of AL neurons, which suggests that the gaseous signaling 

molecule, nitric oxide (NO), has a role in processing olfactory 

information. To determine if NO is produced by odorant-stimulated 

ORNs, we used real-time imaging with a fluorescent NO marker, DAF- 

FM diacetate, to record odorant-stimulated NO production in AL 

glomeruli. Odorants caused a reproducible, spatially-distinct, and 

concentration-dependent production of NO. Different plant odorants 

evoked spatially-distinct patterns of NO production in sexuallyisomorphic 

glomeruli in males and females, and pheromone activated 

the sexually-dimorphic macroglomerular complex in males. The NO 

response was concentration-dependent both for pheromone and for 

linalool, a plant volatile. The NO-induced fluorescence was reduced by 

bath-applying NO signaling antagonists. These results show clearly 

that NO is produced in the AL in response to odorant stimulation of the 

antennae. The resulting NO may then stimulate soluble guanylyl 

cyclase in a subset of AL neurons to affect the processing of olfactory 

information. Supported by NIH-NIDCD DC04292 


RESPONSES IN THE MOUSE MAIN AND ACCESSORY 

OLFACTORY BULBS TO GENERAL ODORANTS AND 

PHEROMONES REVEALED BY FMRI 

Xu F. 1, Liu N. 2, Kida I. 3, Schafer M. 4, Rothman D.L. 2, Hyder F. 3, 

Restrepo D. 4, Shepherd G.M. 1 1Neurobiology, Yale University, New 

Haven, CT; 2Yale University, New Haven, CT; 3Diagnostic Radiology, 

Yale University, New Haven, CT; 4University of Colorado Health 

Sciences Center, Denver, CO 

High resolution fMRI has been used to study the responses in the 

mouse main and accessory olfactory bulb (MOB and AOB) to general 

odors and pheromones. General odorants elicited strong signals across 

the MOB; a few odors were also able to activate the AOB. Urine, a rich 

source of pheromones, stimulated both the MOB and the AOB. The 

patterns in the MOB and AOB were distinctly different for urine and 

amyl acetate. The patterns of urines from different strains shared 

significant domains, and correlated well with other mapping methods. 

For both general odors and pheromones, the pattern intensity in the 

MOB increased with concentration, with the pattern topography 

remaining similar. In the AOB, most odors did not significantly 

activate any region at low concentration, but did at high concentration. 

Both pattern intensity and topography were concentration dependent in 

the AOB. However, pheromones stimulated the AOB at lower 

concentrations. Interestingly, the most activated regions were not 

significantly affected by concentration, making the topography of the 

pattern at different concentrations similar, as in the MOB. The 

response time course was slower in the AOB than in the MOB. The 

results give insights into the similarities and differences between 

responses of the MOB and AOB to general odors and pheromones. 

The research is supported by MURI and NIH grants DC-00086 

(GMS) and DC-03710(FH)


MAIN OLFACTORY BULB DETECTION OF SOCIAL 

RECOGNITION CUES IN MOUSE URINE 

Lin D. 1, Katz L.C. 1 1Neurobiology, Duke University, Durham, NC 

In rodents, chemicals present in urine play a critical role in 

reproductive behaviors and mediating aggressive interactions. Both 

behavioral tests and immediate early gene expression indicate that the 

main olfactory bulb (MOB) participates in individual identification. 

Little is known about how urine responsive neurons are organized in the 

MOB, or which semiochemicals in urine carry important information. 

To address these issues, we examined extracellular activity of mitral 

cells in the mouse MOB in response to volatile components of urine 

from different sexes and strains of mice. Recordings from more than 

one thousand cells revealed that less than 5% of neurons responded 

selectively to different sources of urine. The urine responsive cells were 

confined to a small region in the ventral and lateral parts of the MOB. 

To ascribe a role to specific chemicals present in urine, we combined 

gas chromatography with extracellular recording in the MOB, so that 

the activity of individual mitral cells could be monitored while 

delivering the separated urinary components. The majority of neurons 

which showed an excitatory response to complete urine responded 

identically to just a single peak out of the hundreds present in the gas 

chromatogram of mouse urine. Surprisingly, over 20% of the urine 

responsive cells responded to one particular component, which has been 

implicated as a mouse pheromone. Preliminary behavioral data indicate 

the concentration of this pheromone in male mouse urine significantly 

correlates with the duration of female mice investigation of the urine. 

Thus, mitral cells selectively respond to individual components in 

mouse urine, and a disproportionate number of these neurons are 

involved in detecting a volatile pheromone. 


SPATIO-TEMPORAL FIRING RATE INTERACTIONS 

AMONGST AN ENSEMBLE OF MITRAL/TUFTED CELLS 

MAY SUBSERVE ODORANT DISCRIMINATIONS. 

Lehmkuhle M.J. 1, Normann R.A. 1, Maynard E.M. 1 1Bioengineering, 

University of Utah, Salt Lake City, UT 

Populations of output neurons in the mammalian olfactory bulb (OB) 

exhibit distinct spatial and temporal activation patterns when stimulated 

with enantiomers of the same odorant. If, as has recently been 

suggested, a two-stage network of inhibitory and excitatory centersurround 

connections link spatially distributed glomerular activity with 

underlying mitral and tufted neurons within olfactory bulb, then it is 

likely that these interactions affect the ensemble response to odorant 

stimulation. Here we investigate in the anesthetized rat the rate 

response temporal kinetics in neuronal ensembles by comparing pairwise 

response similarity of a population of single- and multi-unit 

mitral/tufted cells aligned to breathing in the presence and absence of 

enantiomers of limonene. Such comparisons can be used to quantify 

differences in the kinetics of the response of one neuron from other 

neurons in the recorded population. It is shown that aligning unit 

responses to the inhalation phase of the animals´ breathing tends to 

synchronize unit responses. Instances of high-similarity and 

dissimilarity within the population are enantiomer-specific with these 

instances occurring for pairs of units recorded over electrode 

separations of 400 µm – 1.7 mm. These results support the centersurround 

hypothesis and indicate that spatio-temporal firing rate 

interactions amongst an ensemble of OB neurons produce odorant 

representations beyond simple firing rates that may subserve odorant 


2 


PRESYNAPTIC CENTER-SURROUND INHIBITION SHAPES 

ODORANT-ELICITED INPUT TO THE MOUSE OLFACTORY 

BULB 

Vucinic D. 1, Cohen L.B. 1, Kosmidis E. 1 1Cellular & Molecular 

Physiology, Yale University, New Haven, CT 

Synaptic transmission from olfactory primary afferents onto neurons 

of the olfactory bulb is modulated by presynaptic GABA receptors 

B 

(e.g. Wachowiak and Cohen, 1999; Ennis et al., 2001; Wachowiak et 

al., 2002). To study the role of this modulatory circuit in vivo we 

recorded the fluorescent signal from Calcium Green-1 dextran, loaded 

into the axon terminals of olfactory receptor neurons, in response to 

odorant presentations to the nose. We bath-applied agonists and 

antagonists of the GABA receptor onto the olfactory bulb and looked 

B 

for an effect of these agents on the amplitude, spatial map and time 

course of odorant-elicited signals. The GABA antagonist CGP46381 

B 

caused a significant and long-lasting increse in the average amplitude of 

glomerular activation in most preparations. Large changes in signal 

amplitude were accompanied by a change in the input map such that 

many weakly activated glomeruli underwent relatively larger increases 

in signal amplitude than the strongy activated ones. We find that the 

magnitude of this effect correlates with how strongly activated the 

surround of a glomerulus is. This finding indicates that a form of 

GABA-mediated center-surround inhibition modifies the sensory input 

map even before the first synaptic transmission, increasing its contrast. 

Supported by NIH grants NS07455 and DC05259. 


LONG-TERM ODOR EXPOSURE INCREASES SURVIVAL 

AND FUNCTIONAL INTEGRATION OF INTERNEURONS IN 

THE OLFACTORY BULB. 

Mirich J. 1, Illig K.R. 1, Brunjes P.C. 1 1Psychology, University of 

Virginia, Charlottesville, VA 

While our previous work indicates that activity is critical for the 

survival of bulbar interneurons, the rules by which new neurons become 

integrated into existing neural circuits remain unclear. If olfactory 

activity guides the functional integration and survival of newly born 

cells, then repeated exposure to an odorant should increase the number 

of cells that participate in the coding of that odor. Adult subjects 

received daily injections of BrdU for 5 days to label a cohort of newly 

born neurons. They were then exposed daily to menthyl isovalerate, ßpinene, 

butyric acid, or mineral oil (control) for 3 weeks. For half of the 

animals in each group, the odorant was paired with Froot Loops to 

increase salience. On the last day, animals were exposed to ultra-pure 

odorants intermittently for 1hr, and tissue stained for BrdU and Fos 

protein. Long-term odor exposure doubled the survival of interneurons 

compared with controls. Double-label immunohistochemistry showed a 

statistically significant increase (44%; p < 0.05) in BrdU/Fos positive 

cells, demonstrating integration of newly born cells during the training 

period. Additional analyses confirmed that new neurons integrated 

specifically into the areas of the bulb activated by the odorant 

presented. This study demonstrates that survival and integration of 

newly born bulbar neurons depends on the odor environment present 

during their development. We conclude that repeated activation of 

synaptic ensembles might change neural requirements, thereby 

influencing the cellular milieu. Supported by NIH grants DC0338 

(NIDCD) and HD07323 (NICHD).


A LIMK DISEASE MODEL REVEALS DEFECTS IN 

GLOMERULAR DEVELOPMENT AND OLFACTORY 

NEURODEGENERATION 

Hing H.K. 1, Ang L. 2, Yao Y. 2, Uemura T. 3, Keshishian H. 4 1Cell and 

Structural Biology, University of Illinois at Urbana-Champaign, 

Urbana, Illinois; 2Cell and Structural Biology, University of Illinois at 

Urbana-Champaign, Urbana, IL; 3Kyoto University Hospital, kyoto, IL; 

4Molecular Cell and Developmental Biology, Yale University, new 

haven, CT 

The molecular mechanism by which the precise connectivity of the 

olfactory map is formed is poorly understood. We have investigated the 

role of the Lim Kinase (Limk) gene in the Drosophila olfactory map 

development. Limk has also been at the center of much attention lately 

because its loss is implicated in the human mental retardation disease, 

Williams Syndrome. We have created a Limk disease model by 

knocking out and overexpressing the fly Limk gene. At the 

neuromuscular junction, loss of Limk leads to enlarged synapses while 

expression of a hyperactive Limk mutant (LimkKd ) leads to stunted 

synapse. Expression of LimkKd in the olfactory receptor neurons 

(ORNs) results in the formation of numerous ectopic glomeruli. The 

ability of the LimkKd to induce ectopic glomeruli is abolished by either 

mutations in the Pak gene or overexpression of cofilin gene. This result 

indicates that Pak, Limk and cofilin function in a signaling pathway to 

regulate synaptogenesis in the fly antennal lobes. Interestingly, loss of 

Limk also leads to an adult-onset, progressive loss of ORN axons from 

the antennal lobes. This adult-onset neurodegeneration phenotype is 

mimicked by increased cofilin expression. In summary, Limk performs 

two functions in vivo, a developmental function in which it regulate 

synapse development and an adult function in which it protects neurons 

from premature demise by keeping cofilin activity in check. 

10 Symposium [ ] Developmental Regulatory Genes in the 

Taste and Olfactory Systems 

MAKING A NEURON: PRONEURAL BHLH FACTORS 

DURING RETINAL AND OLFACTORY DEVELOPMENT 

Vetter M.L. 1 1Neurobiology and Anatomy, University of Utah, Salt 

Lake City, UT 

Basic helix-loop-helix (bHLH) transcription factors play a central 

role in regulating the acquisition of neuronal cell fate in sensory tissues 

such as the olfactory epithelium and neural retina. For example, we 

identified the bHLH factor Xath5 in Xenopus laevis and demonstrated 

that it can regulate neuronal differentiation during retina and olfactory 

placode development. In general, proneural bHLH factors are both 

necessary and sufficient to promote the neural fate and do so by 

activating a core program of neuronal differentiation in progenitors. We 

have performed a differential screen to define the genes that are directly 

regulated by proneural bHLH factors in Xenopus and are examining 

how these genes contribute to the process of neuronal differentiation. 

In addition, specific factors act to regulate the onset of proneural 

gene expression during development. Frizzled 5, which is a 

transmembrane receptor that binds to wnt ligands, is exclusively 

expressed in the developing neural retina during early eye development 

in Xenopus laevis. We used antisense morpholino oligonucleotides to 

disrupt Frizzled 5 expression and found that this receptor regulates the 

onset of neurogenesis during retinal development. In the absence of 

normal Frizzled 5 expression, retinal progenitors fail to activate the 

expression of genes required for neural competence and subsequently 

fail to initiate proneural gene expression on schedule. Thus we can 

place proneural bHLH factors in a genetic cascade that leads to the final 

acquisition of a neural fate. 

3 



COMMON MOLECULAR SIGNALS REGULATING 

PROGRESSION THROUGH THE NEURONAL LINEAGE IN 

OLFACTORY AND OTHER SENSORY EPITHELIA 

Calof A.L. 1, Beites C. 1, Crocker C. 1, Hayashi H. 1, Kim J. 1, Silman E. 1, 

Santos R. 1, Kawauchi S. 1 1Anatomy & Neurobiology, University of 

California, Irvine, Irvine, CA 

To understand how signaling molecules regulate the generation of 

neurons from proliferating stem cells and neuronal progenitors in the 

mammalian nervous system, we have focused on studies of 

neurogenesis in the olfactory epithelium (OE) of the mouse. By 

analyzing neurogenesis in the OE of normal animals and mouse 

developmental mutants, we have identified distinct stages of stem and 

transit amplifying progenitor cells in the differentiation pathway of 

olfactory receptor neurons (ORNs); each of these cell stages can be 

identified by distinct molecular marker(s). Studies of progenitor cells in 

developing and regenerating OE have led to the understanding that (1) 

each progenitor cell type is regulated by signals produced both within 

the OE itself and by its underlying stroma; (2) the same regulatory 

gene(s) play critical roles in neurogenesis in different regions of the 

primary olfactory pathway; (3) the same signaling molecules that 

regulate neurogenesis in OE likely play similar roles in other sensory 

epithelia. Supported by grants to ALC from the NIH (DC03583 and 

HD38761) and March of Dimes. 



SHH SIGNALING AND TASTE BUD MAINTENANCE IN THE 

ADULT MOUSE 

Miura H. 1, Kusakabe Y. 1, Tetsuya O. 1, Ninomiya Y. 2, Hino A. 1 

1National Food Research Institute, Tsukuba, Japan; 2Kyushu 

University, Fukuoka, Japan 

Continuous cell renewal in adult mammalian taste buds implies the 

requirement of inductive signals for growth and differentiation of taste 

bud precursor cells. And they should be dependent on the taste nerve. 

We have previously reported the expression of Sonic hedgehog (Shh) in 

the basal cells of taste buds. Various inductive events are mediated by 

the Shh signal in animal development. In adult taste epithelium, the 

expression of Patched1 (Ptc), Shh receptor, was observed in the 

surrounding region of the Shh expression, where mitotic cells 

contributing to taste buds may be distributed. Moreover, Nkx2.2 

expression was found in taste buds: Nkx2.2 is transiently expressed in 

the neuronal precursor cells in the ventral region of neural tube, being 

activated by Shh signal. The Nkx2.2-expressing cells in the taste buds 

were found to express Mash1, a marker for the neuronal precursor cells. 

These observations suggest that Shh signaling may be involved in the 

taste bud maintenance in the adult mouse. In addition, the denervation 

revealed the strong nerve dependency of the basal cell-specific Shh 

expression in the taste bud. A quick loss of Shh after denervation led 

the decrease of Ptc expression. The decrease might be involved in the 

arrest of precursor cell proliferation after denervation, which causes the 

taste bud disappearance. Shh signaling and the regulatory gene 

expressions in taste buds will be discussed in relation to the taste cellspecific 

genes. This work was supported by Bio-Oriented Technology 

Research Advancement Institution of Japan.

13 Poster [ ] Taste Hedonics & Psychophysics 

UNDERSTANDING VEGETABLE ACCEPTANCE: ROLE OF 

EARLY EXPERIENCE 

Kennedy J.M. 1, Mennella J.A. 1, Beauchamp G.K. 1 1Monell Chemical 

Senses Center, Philadelphia, PA 

Although infants differ substantially in their acceptance of foods 

during weaning, the source of such differences remains a mystery. 

Recently, we have identified a particularly apt system to explore these 

issues: the inherent flavor variations characteristic of infant formulas. 

Within each of these categories of formulas are a number of varieties 

that differ among themselves in formulation and flavor but the 

differences between the categories, and, in particular, between the 

hydrolysate and milk-based varieties in sensory quality (flavor) are 

striking and profound. The present study tested the hypothesis that the 

type of formula fed to infants would influence their acceptance of 

vegetables that shared a similar flavor note (e.g., sulfur volatiles) with 

the formula (e.g., hydrolysate formula). In counterbalanced order, we 

evaluated 87 infants´ acceptance of pureed carrot on one testing day and 

pureed broccoli on the other. Infants who were feeding a hydrolysate 

formula consumed significantly less broccoli relative to carrots when 

compared to those who were currently fed milk based formulas. Such 

findings are consistent with previous research that demonstrated a 

sensory specific satiety following repeated exposure to a particular 

flavor in either formula or mothers´ milk in the short term. This 

research was supported by NIH Grant HD37119. 


ANALGESIC EFFECTS OF INTRAORAL SUCROSE: THE 

MORE THEY LIKE SWEET TASTE, THE BETTER IT 

WORKS? 

Pepino M.Y. 1, Kennedy J.M. 1, Mennella J.A. 1 1Monell Chemical Senses 

Center, Philadelphia, PA 

During infancy and childhood, preference for sweet tastes is 

heightened and sweet-tasting substances can be analgesics. The goal of 

the study was to evaluate individual differences in sweet preferences 

and to determine whether such differences are related to sucrose´s 

analgesic effects in 5- to 10-year-old children and their mothers. To this 

aim, the preferred level of sucrose was determined by using a forcedchoice, 

paired comparison, tracking procedure, and the analgesic effect 

of sweet taste was determined by the Cold Pressor Test. As a group, 

children preferred significantly higher concentrations of sucrose than 

mothers. Ethnic differences in sweet preferences were observed in both 

children and adults such that Blacks preferred significantly higher 

concentrations when compared to Whites. Regardless of race, children 

who preferred high sweet concentrations kept their hand in the cold 

water significantly longer when sucrose was held in their mouths when 

compared to water (p=0.002). These findings suggest that the analgesic 

effects of sweet tastes may be more pronounced in those pre-pubertal 

children who have heightened sweet preference. This research was 

supported by NIH Grants AA09523 and HD37119. 

4 


INFLUENCE OF CONCENTRATION ON TASTE-TASTE 

INTERACTIONS IN FOODS BY ELDERLY AND YOUNG 

Mojet J. 1, Heidema J. 2, Christ-Hazelhof E. 2 1Consumer & Market 

Insight, Agrotechnology and Food Innovations, Wageningen, 

Netherlands; 2Unilever Research and Development, Vlaardingen, 

Netherlands 

An increase in concentration of one of the tastants in a `real food´ 

might not only effect the perception of the taste quality of the 

manipulated tastant, but also the other perceivable taste qualities. The 

influence of concentration increase of sodium chloride, potassium 

chloride, sucrose, aspartame, acetic acid, citric acid, caffeine, quinine 

HCl, monosodium glutamate (MSG), and inosine 5´-monophosphate 

(IMP) on the other perceivable taste qualities was studied in different 

foods.Twenty-one young (19-33 years) and 21 older subjects (60-75 

years) rated the saltiness, sweetness, sourness, bitterness and umami 

taste of the food stimuli on 9-point scales. Repeated measures and 

multivariate analysis showed that an increasing concentration of sodium 

and potassium chloride diminished the sweetness more for the young 

than for the elderly, but enlarged the bitterness, sourness and umami 

taste in tomato soup more for the elderly than for the young. The 

saltiness of ice tea was decreased with an increase in sucrose, while a 

larger decrease in bitterness was found for the young than for the 

elderly. An increase in sucrose or aspartame concentration in ice tea 

also decreased the sourness. No influence was shown by an increment 

of acetic acid or citric acid in mayonnaise. The increasing concentration 

of caffeine and quinine induced a decrease in sweetness of the 

chocolate drink. The increase in MSG showed an increase in the 

saltiness of broth, whereas an increase in IMP led to a decrease in 

saltiness and an increase in sweetness. Young subjects took advantage 

of their sense of smell in the no noseclip condition. 

16 Slide [ ] Taste Hedonics & Psychophysics 

ACCOUNTING FOR BETWEEN-SUBJECT VARIANCE IN 

DISCRIMINATION AND PREFERENCE TASKS 

Delwiche J. 1, Liggett R. 1 1Food Science and Technology, Ohio State 

University, Columbus, OH 

The binomial statistic is typically used to determine the number of 

correct discriminations needed to indicate a significant difference 

between items. This statistic does not account for differences between 

subjects, making it inappropriate to combine responses across subjects 

and repetitions, which is often something researchers would like to do. 

The beta-binomial model is able to account for between-subject 

variance (measured by gamma), making such analyses possible. This 

study examined panel overdispersion (gamma) for one group of 

subjects (53-58 subjects per group, depending on stimuli set) 

performing two replications of both paired comparisons (2AFC) and 

paired preferences on the same stimuli set. Stimuli tested included fruitflavored 

beverages (with different sucrose levels), and snack foods 

(with different fat contents). Results showed that significant 

overdispersion with one task were not predictive of overdispersion in 

the other. Further, the stability of gamma across discrimination methods 

(2AFC, 3AFC, triangle, and duo-trio) for a group of 103 subjects was 

examined. Stimuli were cherry-flavored fruit beverages at two different 

sucrose levels, and order of the discrimination tasks was counterbalanced 

across subjects. Results indicated that gamma was largely 

consistent across the 2AFC, 3AFC and triangle tasks, but it was higher 

in the duo-trio task. In all cases, the use of the beta-binomial model 

allowed for the combining of discriminations across subjects and 

replications, increasing the discrimination power achieved for a given 

panel size. This project was self-funded.


RESPONSES OF PROP TASTER GROUPS TO VARIATIONS IN 

TASTES AND ORAL IRRITATION WITHIN A BEVERAGE 

Prescott J. 1, Campbell H. 2, Roberts C. 2 1Psychology, James Cook 

University, Cairns, QLD, Australia; 2Sensory Science Research Centre, 

University of Otago, Dunedin, New Zealand 

Despite considerable evidence that variations in sensitivity to the 

bitterness of 6-n-propylthiouracil (PROP) are also reflected in 

responses to both other tastes and also chemesthetic qualities in 

solution, there has been little research examining the impact of PROP 

sensitivity on response to these sensory modalities in foods or 

beverages. The present study examined responses of PROP taster 

groups to systematic variations in sourness and oral irritation in a 

carbonated beverage. Taster groups were defined according to ratings 

of a 0.0032 M PROP solution using the labelled magnitude scale 

(LMS). Using the LMS, Ss rated the sweetness, sourness and oral 

irritation of carbonated fruit drinks that systematically varied in citric 

acid (0.32, 0.64, 1.28, 2.56% w/v) and CO2 (25, 50, 75 psi) 

concentrations. Ratings of sourness as a function of citric acid, and 

irritation as a function of both citric acid and CO2 levels, were 

significantly different between groups, with highest ratings for STs and 

lowest for NTs. There were no group differences for sweetness ratings. 

These data are some of the first to show PROP taster group differences 

in tastes and irritation within a real product, and provide a basis for 

reported differences of PROP groups in their hedonic responses to 

foods. 


GENETIC SENSITIVITY TO 6-N-PROPYLTHIOURACIL 

(PROP), AND PERCEPTION OF HIGH-INTENSITY 

SWEETENERS IN MODEL SOFT DRINKS 

Tepper B.J. 1, Zhao L. 1 1Food Science, Rutgers University, New 

Brunswick, NJ 

Intense sweeteners (e.g., saccharin, aspartame, and acesulfame-K) 

impart sweetness, bitterness and other aftertastes to foods. Individual 

variation in sensitivity to sweeteners is well known. Those who are 

genetically sensitive to the bitterness of PROP perceive more sweetness 

and bitterness from saccharin. Findings for other sweeteners are less 

clear. This study examined the role of PROP taster status in perception 

and acceptance of intense sweeteners in citrus-flavored model soft 

drinks. Young adults were classified as non-tasters (NT; n=29) or 

supertasters (ST; n=30) of PROP using a filter paper screening method 

(Zhao et al., 2003). The following sweeteners were used: 10% and 8% 

high fructose corn syrup (HFCS) (controls), sucralose (SUC), 

aspartame (ASP), acesulfame-K (ACE), ASP/ACE and SUC/ACE. 

Subjects rated the intensity of nine attributes with a 15-cm line scale 

and liking with the Labeled Affective Scale (LAM). ST perceived more 

bitterness from SUC/ACE and 8% HFCS (p=0.05); ACE was 

marginally more bitter to ST (p=0.06). ST also perceived more 

persistence of sweetness across all sweeteners (p=0.05). 3-dimensional 

models best described the perceptions of the sweeteners. For ST the 

dimensions were bitterness (43% variance), persistence of sweetness 

(22%), and carbonation (11%). For NT the dimensions were: sweetness 

and citrus flavor (37%), bitterness (24%), and carbonation/thickness 

(11%). Liking was uniquely related to low bitterness for NT but was 

related to multiple attributes for ST. These data suggest that ST 

experience intense sweeteners differently than NT but these differences 

play a modest role in soft drink acceptance. Supported by McNeil 

Nutritionals. 

5 


6-N-PROPYLTHIOURACIL (PROP) BITTERNESS AND 

TASTES FROM ALCOHOLIC AND NON-ALCOHOLIC 

BEVERAGES IN OF-AGE UNDERGRADUATES 

Lanier S. 1, Hayes J. 2, Duffy V.B. 1 1Dietetics, University of Connecticut, 

Storrs, CT; 2Nutritional Science, University of Connecticut, Storrs, CT 

Previous research has shown associations between taste genetics and 

alcohol behaviors. We tested the taste genetic and alcohol intake 

relationship and linked this relationship to oral sensations from 

alcoholic beverages. Taste genetics was measured via perceived PROP 

bitterness; nontasters taste PROP as mildly bitter while supertasters as 

intensely bitter. Sixty-two adults (mean age=22 years) used the general 

Labeled Magnitude Scale to rate PROP bitterness and oral sensations 

from and preference for sampled Pilsner beer, scotch, strong black 

coffee and unsweetened grapefruit juice. Subjects also completed 

validated questionnaires on behaviors toward alcohol. Data were 

analyzed with regression analyses. Those who tasted greater PROP 

bitterness reported all beverages as more bitter and less preferred except 

beer. Neither PROP bitterness nor beer bitterness were strong 

predictors of beer preference. PROP nontasters tasted scotch as less 

bitter but more sweet than did supertasters. Those who tasted scotch as 

more bitter consumed less alcohol; PROP bitterness only tended to 

associate with alcohol intake. Beer sensations did not associate 

significantly with alcohol intake. Summary: Nontasters get less 

negative (bitter) and more positive (sweet) tastes from alcohol than 

supertasters. Sensory differences translated into greater liking for bitter 

beverages by nontasters, except for beer. Positive social influences to 

drink beer on college campuses may override negative oral sensations 

to hinder intake. (NRICGP/USDA 2002-00788 funded) 


PERSONALITY TRAITS AND PROP SENSITIVITY 

White T.L. 1, Longo M. 2 1Psychology, Le Moyne College, Syracuse, NY; 

2Education, Syracuse University, Syracuse, NY 

Although theories of personality vary widely, most trait theories 

include the dimension of Introversion-Extroversion. Physiological 

differences are thought to exist between people who are represented by 

the extremes on this dimension, with introverts experiencing a high 

level of baseline arousal. This higher arousal level suggests that 

introverts experience elevated sensitivity to perceptual stimuli, 

including sour tastes (Eysenck, 1976), as compared to extroverts. As the 

ability to taste PROP can also affect taste sensitivity, the current study 

investigated the relationship between PROP sensitivity and personality 

traits, particularly introversion. The NEO-PI, a personality measure that 

evaluates 5 personality traits, was administered to 50 college students 

(39 women, 11 men). After completing the personality test, participants 

were given a PROP sample and asked to rate its intensity on a labeled 

magnitude scale (LMS; Green, 1993). No correlation was found 

between introversion, conscientiousness, or openness to experience and 

PROP tasting ability. However, a relationship was seen between the 

domain trait of neuroticism and intensity ratings of PROP on the LMS 

(r=0.346, p=0.014), in particular those facets concerned with anxiety 

and depression. Although agreeableness was not overall associated, the 

facet concerned with trust was inversely (r=-0.336, p=0.017) associated 

with LMS Scores. These associations suggest that personality traits may 

interact with genetic abilities as partial explanation for individual 

differences food preferences.


OROSENSORY AND GENETIC TASTE (GT) MARKERS 

PREDICT ALCOHOL INTAKE ACROSS AGE COHORTS 

Hayes J.E. 1, Chapo A. 2, Bartoshuk L. 2, Duffy V.B. 3 1Nutritional 

Sciences, University of Connecticut, Storrs, CT; 2Surgery, Yale 

University, New Haven, CT; 3Dietetics, University of Connecticut, 

Storrs, CT 

Supertasters, identified by heightened 6-n-propylthiouracil (PROP) 

bitterness and fungiform papilla (FP) number, report greater negative 

and less positive sensations from alcohol, possibly hindering intake. 

Work by others (eg, Kranzler et al) show positive associations between 

oral sensations and intake, findings that contradict GT-mediated effects. 

To characterize age, sensory, and GT effects on intake, 99 healthy 

women (aged 20-84) used the general Labeled Magnitude Scale to rate 

PROP bitterness, regional and whole mouth intensity of prototypical 

tastants and ethanol on the tongue tip. Intake was assessed via a 

frequency interview and FP by videomicroscopy. In young subjects, 

lower PROP bitterness and greater whole mouth taste were significant 

predictors of greater alcohol intake, yet a spatial taste measure 

diminished the predictive ability of whole mouth taste. Across the entire 

sample, age (young>aged), FP number (higher number, less intake) and 

whole-mouth taste responses (greater intensity, more intake) were 

significant predictors of intake. Cross quality whole-mouth and chorda 

tympani, but not circumvallate, intensity showed age-related loss. In 

summary, GT markers and additional taste markers contribute to 

predicting alcohol intake across age cohorts. Reasons for higher taste 

response associating with greater alcohol intake remain unclear. Spatial 

interactions among sensory nerves could heighten whole mouth 

orosensation (eg, sweetness) and change the sensory appeal of alcohol. 

(NRICGP/USDA 2002-00788) 


INFLUENCE OF FATTY ACID SENSITIVITY ON TASTE 

PERCEPTION 

Smeets M. 1, Weenen H. 2, De Wijk R. 2, Mojet J. 1, Westerterp M. 3 

1Agrotechnology & Food Innovations, Wageningen, Netherlands; 

2Wageningen Centre for Food Sciences, Wageningen, Netherlands; 

3Human Biology, Maastricht University, Maastricht, Netherlands 

Following previous work (Gilbertson et al., Kamphuis et al.) 

demonstrating chemosensitivity to fatty acids in the taste system, we 

investigated whether sensitivity to fatty acids in humans: 

1. is influenced by olfaction 

2. is associated with differences in taste perception in general. 

Methods: A group of (linoleic acid) LA-tasters (≥ 9 out of 10 correct 

detections of 10 µM LA) was compared to a non-taster group (n=20 

total). To investigate 1) triangle tests were conducted using 0 % fat 

mayonaise with and without LA (10 µM), with nose clips on and off. 

To investigate 2) taste profiles were generated for various 

products/solutions containing e.g. LA and basic tastants, with and 

without noseclips. 

Results: 

1. LA-Tasters showed above-chance performance without noseclips 

(p=0.04), but not with noseclips. Non-tasters did not perform above 

chance. 

2. There was a main effect of taster status (p


INHIBITION OF BITTER TASTE BY ZINC AND NA- 

CYCLAMATE 

Keast R.S. 1, Breslin P.A. 2 1Monell Chemical Senses Center, 

Philadelphia, PA; 2Psychophysics, Monell Chemical Senses Center, 

Philadelphia, PA 

Previous research has shown that zinc is a potent inhibitor of the 

bitterness of quinine-HCl (Keast, 2003), and the sweet taste of most 

sweeteners (except Na-cyclamate) (Keast et al., 2004). We investigated 

the influence of zinc on perceived bitterness of six structurally 

divergent bitter compounds. We also determined the impact of a 

combination of zinc & Na-cyclamate or zinc & sucrose on the bitterness 

of specific compounds. 

In experiment one, six diverse bitter tasting compounds (Quinine- 

HCl (QHCl), Tetralone (TET), Sucrose octaacetate, Dextromethorphan, 

Denatonium Benzoate (DB), and Pseudoephedrine (PSE)) were 

matched for `moderate´ bitterness intensity. To these compounds one 

of five salts was added: 25 or 300mM Na acetate, 25mM Mg sulfate, 

25mM Mg acetate, and 25mM Zn sulfate. All possible binary 

combinations of bitter compounds and salts were tested. In experiment 

two, the influence of Zn sulfate on bitter-sweet mixtures was 

investigated. The bitter compounds used were DB and PSE, and the 

sweet compounds were sucrose and Na-cyclamate. 

Zn sulfate, 300mM Na acetate, and Mg acetate significantly 

inhibited bitterness (p

29 Poster [ ] Taste: Fats 

THE GUSTATORY SENSATION FROM FREE FATTY ACID 

Kawai T. 1, Nishiduka T. 1, Kajii Y. 2, Shingai T. 2, Kuwasako T. 3, Hirano 

K. 3, Yamashita S. 3, Kawada T. 1, Fushiki T. 1 1Graduate School of 

Agriculture, Kyoto University, Kyoto, Kyoto, Japan; 2Graduate School 

of Medical and Dental Sciences, Niigata University, Niigata, Niigata, 

Japan; 3Graduate School of Medicine, Osaka University, Suita, Osaka, 

Japan 

Fat in food often increases the palatability of food, even though it 

does not give us obvious taste by itself. Some researches have reported 

that taste cells recognize free fatty acid, a hydrolysate from common 

dietary fat, though the free fatty acid has not be defined as one of 

tastants. Its perceptual mechanism is still unclear. We demonstrated 

immunohistochemically that CD36, one of fatty acid transport proteins, 

was localized on the apical part of the taste cells isolated from rat 

vallate papillae. This localization supports the hypothesis that CD36 

plays a role in the oral recognition of dietary fat. In this study, we used 

CD36-null mice for behavioral studies and nerve recordings and 

compared with the wild type mice that had the same background. The 

wild type mice preferred oleic acid solution to mineral oil solution in 

short-time two-bottle preference tests, but the CD36-null mice did not 

show the preference for either solution. Neural recording revealed that 

small but significant response to oleic acid was observed on the lingual 

branch of glossopharyngeal nerve in the wild type mice, but not in the 

CD36-null mice. These results suggest that gustatory signal of fat was 

conveyed via the lingual branch of glossopharyngeal nerve and that the 

CD36 molecule, which exists on the tongue innervated by the lingual 

branch of glossopharyngeal nerve, plays an important role in enjoying a 

taste of fatty acid. 


PROP TASTER STATUS AND PERCEPTION OF FATS AND 

FREE FATTY ACIDS 

Armstrong C.L. 1, Mattes R. 1 1Department of Foods and Nutrition, 

Purdue University, West Lafayette, IN 

PROP tasters, especially supertasters, are reportedly better able to 

perceive the level of fat in foods than PROP non-tasters. This study 

tested perception of fat in both foods and free fatty acids in water. 

PROP taster status was determined by the 5-solution method. To date, 

7 non-tasters, 12 tasters and 7 supertasters have been tested. Subjects 

were randomly presented 5 ml samples of milk, (0.00, 3.25, 10.00, 

18.00, 36.00% fat/wt), 5 ml of vanilla pudding (4.1, 8.2, 16.3, 24.4, 

29.7% fat/wt) and 5 gm of brownies (8.0, 16.0, 24.0, 31.8, 35.6% 

fat/wt) and rated the level of fat in duplicate using the gLMS. Milk and 

vanilla pudding were served at 7° C and brownies at 22° C. To mask 

texture, oleic and linoleic acids (0.40, 0.71, 1.267, 2.25, 4.00% wt/wt) 

were suspended in a solidified unflavored gelatin starch-thickened 

water mixture and 5 gm samples were served at 22° C. Stearic acid (0.5, 

1.0, 2.0, 4.0, 8.0% wt/wt) was suspended in starch-thickened water and 

5 ml samples were served at 71° C. Samples were randomly presented 

in duplicate and the level of fat rated using the gLMS. Subjects 

correctly ranked the fat levels (p < 0.0001) in all foods and free fatty 

acids solutions, but no differences were observed between PROP taster 

groups. These data demonstrate a taste component for free fatty acids, 

but no differences in fat perception based on PROP taster status. This 

research was funded in part by the Rose Marie Pangborn Scholarship to 

CLA and NIH Grant #DK045294. 

8 


FAT TASTE - ARE FREE FATTY ACIDS OR CONJUGATED 

DIENES THE EFECTIVE STIMULUS? 

Chalé A. 1, Burgess J.R. 2, Mattes R.D. 1 1Foods and Nutrition, Purdue 

University, W Lafayette, IN; 2Foods & Nutrition, Purdue University, W 

Lafayette, IN 

"Fattiness" is hypothesized to be a basic taste quality, most 

efficiently elicited by long-chain poly- and monounsaturated fatty acids. 

Free fatty acids (FFA) have been prepared in solutions containing an 

emulsifier or thickening agent to mask textural cues or in foods. 

Whether the effective stimulus was the FFA or oxidation product has 

not been established. This work examined the effects of addition of 

EDTA and sonification (to reduce oxidation) on oxidation product 

concentration. Linoleic acid was prepared at a concentration of 

10mg/dl and mixed in a solution of 5% Acacia and de-mineralized 

water. The concentration of EDTA was 0.01%. Samples were sonified 

for 40 minutes. This preparation increased linoleic acid recovery 100X 

over a simple oil-water mixture. These results suggest extensive 

degradation of FFAs in previously used fat taste samples resulting in 

conjugated dienes that may be effective taste stimuli. This is being 

explored through psychophysical studies. 

32 Poster [ ] Vomeronasal Organ 

REGULATOR OF G-PROTEIN SIGNALING PROTEINS IN 

THE VOMERONASAL ORGAN OF GARTER SNAKES 

Wang D. 1, Liu W. 2, Chen P. 1, Halpern M. 3 1Biochemistry, Downstate 

Medical Center, Brooklyn, NY; 2Anatomy and Cell Biology, Downstate 

Medical Center, Brooklyn, NY; 3Anatomy & Cell Biology, Downstate 

Medical Center, Brooklyn, NY 

The response to prey chemoattractants in garter snakes is mediated 

by the vomeronasal (VN) system.The chemosignal transduction 

pathway in the VN epithelium involves the binding of agonist to its Gprotein 

coupled receptors leading to activation of Gi/o-proteins which 

in turn activate PLC, converting PIP2 to IP3 and DAG, and resulting in 

a transient cytosolic Ca2+ increase and changes in membrane potential. 

However, the desensitization mechanism so far remains unknown. We 

found that the chemoattractant-induced signal is modulated by two 

membrane-bound proteins, p42/44, which modulate the exchange of 

GTP for GDP on the Ga subunit. During recent years, regulators of Gprotein 

signaling (RGS proteins) have been identified. These proteins 

enhance the activity of GTPase intrinsic to G alpha subunits and have 

been shown, in a wide number of biological systems, to play an 

important role in modulating agonist-induced signals. Using 

commercially available RGS antibodies, we detected the expression of 

several isotypes of RGS proteins in the VN sensory epithelium of garter 

snakes. In addition, by screening a snake VN cDNA library, we 

obtained several clones which show high homology to RGS2, RGS3 

and RGS4. These RGSs may play a role in desensitization of 

chemoattractant-induced signal transduction. 

Supported by NIDCD Grant #DC03735


CHEMOSIGNAL TRANSDUCTION IN THE VOMERONASAL 

ORGAN OF GARTER SNAKES: CHEMOATTRACTANT- 

INDUCED MEMBRANE POTENTIAL CHANGES 

Liu W. 1, Dalton W. 2, Chen P. 2, Halpern M. 3, Cinelli A. 1 1Anatomy and 

Cell Biology, Downstate Medical Center, Brooklyn, NY; 2Biochemistry, 

Downstate Medical Center, Brooklyn, NY; 3Anatomy & Cell Biology, 

Downstate Medical Center, Brooklyn, NY 

We have demonstrated previously that in the snake vomeronasal 

(VN) organ chemoattractant (ESS) produce transient calcium cytosolic 

accumulation in the dendritic regions of VN neurons via two pathways: 

calcium release from IP3-sensitive stores and a plasma membrane 

calcium influx. Using voltage-sensitive dyes, here we characterize the 

functional role of these events during VN chemosensory transduction. 

ESS evokes optical depolarizations which exhibit a time course similar 

to the EVG, but shorter than VN calcium transients. Peak 

depolarization in the apical VN region are reduced but not suppressed 

in the absence of external calcium, indicating that they probably depend 

on non-selective cation channels. Depletion of all internal calcium 

stores evokes a reduction of these depolarizations, which is not 

observed when responses are evoked by potassium depolarization. 

Interestingly, the depletion of ryanodine-sensitive calcium stores fails to 

evoke this reduction, and instead increases the duration of 

depolarizations in the cell body region. This effect is suppressed when 

potassium currents are blocked. These results support the notion of a 

functional compartmentalization between different calcium stores and 

indicates a dual and opposite action of calcium release in snake VN 

neurons during chemosensory transduction. Calcium release by IP3sensitive 

stores appears to enhance the initial dendritic depolarization, 

while calcium release by ryanodine stores seems to activate repolarizing 

potassium currents controlling the duration of these responses. 

Supported by NIDCD Grant #DC03735 


VOMERONASAL ORGAN SIGNAL TRANSDUCTION IN THE 

CHILEAN LIZARD, LIOLAEMUS BELLII. 

Labra A.L. 1, Fadool D.A. 1 1Prog. in Neurosci. & Mol. Biophysics, 

Florida State University, Tallahassee, FL 

Specimens of Liolaemus bellii (Chilean lizard) were live-captured in 

the mountains of central Chile and transported to the U.S.A. to 

determine their suitability for cellular studies of the vomeronasal organ 

(VNO). Rhodamine-conjugated dextran plus 2% Triton X-100 was 

introduced into the vomeronasal (VN) orifice to confirm the location of 

the VN epithelium and its degree of compartmentalization from the 

MOE. After migration of the vital dye for two weeks, individual 

vomeronasal sensory neurons (VSNs) were distinctly labeled and 

showed a bipolar morphology as reported in the VNO of all other 

vertebrates. Ten µm cryosections of the VN epithelium were intensely 

labeled with antibodies against Giα1-3 and Gβ G-proteins. Extracts 

were prepared (1:300 dilution) from three body source secretions (skin, 

feces, cloacal) known to contain pheromones mediating chemical 

communication in these animals. Three mM agmatine (AGB) was 

mixed with one of the body source secretions or control saline and 

lizards were stimulated with the pheromone plus AGB mixture to 

histologically map and determine secretion rank-order effectiveness. 

Using L-cysteine-activated papain for VSN isolation, we were able to 

preserve both voltage and chemosignal-activated conductances (n=69 

total recordings) using recording and pipette solutions optimized for 

turtle preparations. The tuning and percentage of chemosignal-activated 

responses (25 of 46 VSNs, 54% response rate), when presented a panel 

of five chemical extracts, will be favorable for future single cell 

electrophysiology studies combined with a distinct cadre of quantifiable 

behavioral displays such as the tongue flick, head bob, and scent 

marking. Supported by NSF WISE grant. 

9 


PROTEIN INTERACTIONS WITH THE TRPC2 ION CHANNEL 

IN THE VOMERONASAL ORGAN (VNO). 

Brann J.H. 1, Fadool D.A. 1 1Prog. in Neuroscience & Mol. Biophysics, 


The role of the inositol 1,4,5-trisphosphate (IP )second messenger 

3 

system in vomeronasal sensory neurons (VSNs) of the vomeronasal 

organ (VNO) is unclear. Furthermore, how the functional connections 

between the type 3 IP receptor (IP R3) and transient receptor potential 

3 3 

channel type 2 (TRPC2) may influence the cationic receptor potential is 

also unknown. We have previously demonstrated that IP R3 and 

3 

TRPC2 have an overlapping expression pattern in rodent VNO and 

participate in a protein-protein interaction. Here we sought to 

demonstrate a functional role for the IP R3/TRPC2 protein complex. 

3 

Pheromone-evoked whole-cell currents were blocked in 4 of 5 VSNs 

when a peptide, directed against the interaction domain between 

IP R3/TRPC2, was included in the recording pipette held (Vh) at –60 

3 

mV. Under our recording conditions, pipette dialysis of 240 mM IP3 failed to evoke whole-cell current in 20 of 20 VSNs tested. Typical 

antagonists of the IP R (ruthenium red, 2-APB) also failed to block 

3 

pheromone-evoked currents. SDS-PAGE and Western analysis of male 

and female VNO tissue reveals expression of one or more of the long 

isoforms of the adaptor protein Homer (1b, 1c, 2a, 2b, and 3; 45 kDa) 

as well as neuronal Shc (66, 53, 46 kDa), an adaptor protein known to 

communicate G protein-coupled receptor (GPCR) and receptor tyrosine 

kinase (RTK) activation. The IP R3/TRPC2 protein complex may be 

3 

associated within a larger protein scaffold whereby IP and/or adaptor 

3 

proteins could subserve regulatory functions of the primary 

transduction current. Supported by F31 DC06153. 


SPECIES SPECIFICITY IN RODENT PHEROMONE 

RECEPTOR REPERTOIRES 

Lane R.P. 1, Young J. 2, Newman T. 2, Trask B.J. 2 1Molecular Biology 

and Biochemistry, Wesleyan University, Middletown, CT; 2Division of 

Human Biology, Fred Hutchinson Cancer Research Center, Seattle, WA 

The mouse V1R putative pheromone receptor gene family consists of 

at least 137 intact genes clustered at multiple chromosomal locations in 

the genome. Species-specific pheromone receptor repertoires may 

partly explain species-specific social behavior. We conducted a 

genomic analysis of an orthologous pair of mouse and rat V1R gene 

clusters to test for species-specificity in rodent pheromone systems. 

Mouse and rat have lineage-specific V1R repertoires in each of three 

major subfamilies at these loci as a result of post-speciation 

duplications, gene loss, and gene conversions. The onset of this 

diversification roughly coincides with a wave of Line1 (L1) 

retrotranspositions into the two loci. We propose that L1 activity has 

facilitated post-speciation V1R duplications and gene conversions. In 

addition, we find extensive homology among putative V1R promoter 

regions in both species. We propose a regulatory model in which 

promoter homogenization could ensure that V1R genes are equally 

competitive for a limiting transcriptional structure to account for 

mutually exclusive V1R expression in vomeronasal neurons.


EXPRESSION PATTERN OF GENES FOR NOTCH 

SIGNALING PATHWAY IN MOUSE VOMERONASAL ORGAN 

DURING ONTOGENY AND REGENERATION AFTER 

REMOVAL OF ACCESSORY OLFACTORY BULB. 

Wakabayashi Y. 1, Ichikawa M. 2 1Research Fellow of the Japan Society 

for the Promotion of Science, Tokyo, Japan; 2Dep Basic Tech and 

Facilities, Tokyo Metropol Inst Neurosci, Tokyo, Japan 

Vomeronasal receptor neurons (VRNs) proliferate and differentiate 

continuously throughout life. Proliferation of VRNs mainly occurs in 

the marginal region of the sensory epithelium of adult vomeronasal 

organ (VNO). The Notch signaling pathway is involved in cell fate 

decisions and differentiation during developmental CNS. We have 

studied whether Notch signaling pathway involves in differentiation 

and proliferation of VRNs during ontogeny and regeneration. 

In this study, we examined the expression patterns of Notch and 

their ligands, Delta and Jagged, using in situ hybridization during 

ontogeny and regeneration after removal of accessory olfactory bulb 

(AOBX) in mice. In adult VNO, a few Notch1(+), Delta1(+) and 

BrdU(+) cells appeared only in the marginal region, whereas Jagged2 

was expressed in all VRNs. Notch1(+), Delta1(+) and BrdU(+) cells 

located close to the basal lamia at embryonic days 14.5 and 16.5, 

whereas expression level of Jagged2 was very low in comparison with 

adult. At AOBX day2, number and location of Notch1(+), Delta1(+) 

and BrdU(+) cells did not change. Expression pattern of Jagged2 did 

not change. At AOBX day7, large amount of Notch1(+), Delta1(+) and 

BrdU(+) cells appeared in the marginal region, whereas expression 

pattern of Jagged2 did not change. These results suggested that the 

interaction of Notch1(+) and Delta1(+) cells play important roles in 

vomeronasal neurogenesis of VNO during ontogeny as well as 

regeneration after AOBX mice. 


THE ROLE OF THE VOMERONASAL SYSTEM IN FOOD 

PREFERENCES OF THE GRAY SHORT-TAILED OPOSSUM, 

MONODELPHIS DOMESTICA 

Daniels Y. 1, Halpern M. 2, Zuri I. 1 1Anatomy and Cell Biology, 

Downstate Medical Center, Brooklyn, NY; 2Anatomy & Cell Biology, 

Downstate Medical Center, Brooklyn, NY 

The vomeronasal system (VNS) is usually considered primarily a 

pheromone-detecting system. In snakes and lizards, this system is also 

important for feeding behavior. To date, no studies have reported 

feeding deficits in mammals deprived of a functional VNS. M. 

domestica is considered a primitive mammalian species that was 

recently introduced into laboratories. Since these opossums respond to a 

variety of foods, they are a good model to investigate the role of the 

VNS in food preferences in mammals. 

The six male and seven female gray short-tailed opossums used in 

this study were simultaneously presented with four foods, one from 

each of the following food groups: fruits (apples, oranges, peaches, 

cantaloupes), meats (mealworms, chicken, pork, crickets), processed 

vegetables (raisin bran, cheerios, whole wheat bread, bagel) and 

unprocessed vegetables (corn, peppers, carrots, broccoli). Before 

blocking access to the vomeronasal organ (VNO) with gel foam and 

Crazy Glue, the opossums selected meats most frequently and fruits 

more frequently than processed and unprocessed vegetables. Following 

VNO blockage, the opossums demonstrated no preference between the 

different food groups. This study suggests that without a functional 

vomeronasal organ, the food preferences of gray short-tailed opossums 

are significantly impaired. 

Supported by NIDCD Grant # DC02745. 

10 

39 Slide [ ] Vomeronasal Organ 

CHEMO-INVESTIGATORY BEHAVIOUR OF MALE MICE IN 

DETECTING ESTRUS: ROLE OF OLFACTORY- 

VOMERONASAL SYSTEM 

Raman S.A. 1 1Animal Scinece, Bharathidasan University, 

Trichirappalli, India 

S.ACHIRAMAN AND G.ARCHUNAN 

Department of Animal Science, Bharathidasan University 

Tiruchirappalli-620 024, Tamilnadu. 

INDIA 

achiraman_s@yahoo.co.in 

The aim of the present study is to evaluate whether the male 

mouse is capable of discriminating the female urinary odour of different 

reproductive phases (with a view to detect estrus using Y-maze 

apparatus and to establish the relationship of olfactory - vomeronasal 

system and chemo-investigatory behaviour in estrus detection. Hence, 

normal, vomeronasal organ (VNO)-ablated and Zinc Sulphate-irrigated 

mouse were used as test animals. Various behaviours such as frequency 

of visit, duration of visit, sniffing, licking, body rubbing and grooming 

were recorded. The normal mice frequently visited and devoted more 

time in delivering various behaviours towards the estrus urine sample in 

comparison to that of non-estrus urine. The VNO-ablated mice showed 

significant reduction in response to estrus urine (duration of visit and 

self-grooming) than that of ZnSO4-irrigated mice. However, the 

ZnSO4-irrigated mice showed significant reduction in frequency of 

visits to the urine samples. These results clearly reveal that the VNO 

play a significant role in the detection of estrus in mice. The present 

results also suggest that male mice preferentially communicate sexual 

interest via self-grooming towards the opposite sex. By self-grooming 

at higher rates, male mice may be broadcasting scents to attract 

potential mates or to inform their willingness to mate. 


NEUROGENESIS, MIGRATION AND APOPTOSIS IN THE 

VOMERONASAL EPITHELIUM OF ADULT MICE 

Martinez-Marcos A. 1, Quan W. 2, Jia C. 2, Halpern M. 3 1Departamento 

de Ciencias Medicas, Universidad de Castilla-La Mancha, Albacete, 

Albacete, Spain; 2Anatomy and Cell Biology, Downstate Medical 

Center, Brooklyn, NY; 3Anatomy & Cell Biology, Downstate Medical 

Center, Brooklyn, NY 

Neurogenesis in the adult mouse vomeronasal organ appears to occur 

in the central regions, but is more prevalent at the edges of sensory 

epithelium. Basal cells at the center of the epithelium participate in cell 

replacement. It is unknown whether dividing cells at the edges 

constitute a reservoir for growth, become apoptotic or participate in 

neural turnover. This latter possibility implies a process of horizontal 

migration. The present work addresses this controversy by injecting 

bromodeoxyuridine in adult mice and allowing them to survive for 

various intervals. The vertical and horizontal position of labeled cells 

was analyzed as a function of time. Both, vertical and horizontal 

migration of labeled cells were detected. Cells at the center of the 

epithelium migrate vertically to become neurons as demonstrated by coexpression 

of olfactory marker protein. Cells at the edges migrate 

horizontally toward the center. After 42 days, however, they have 

migrated less than 10% of the distance from the edge (0%) to the center 

of the epithelium (100%), thus making it likely that if these cells 

participate in neural turnover it is only in marginal regions. The pattern 

of distribution of apoptotic cells has been studied and, interestingly, it is 

similar to that of dividing cells. These results support the idea that 

sensory cell renewal in the mouse vomeronasal organ occurs through a 

process of vertical migration. Supported by grant DC02745.


NEW METHOD OF VOMERONASAL NERVE TRANSECTION 

LEAVES THE OLFACTORY SYSTEM INTACT. 

Matsuoka M. 1, Norita M. 2, Costanzo R.M. 3 1Niigata University 

Graduate School of Medical and Dental Sciences, Niigata, Niigata, 

Japan; 2Division of Neurobiol. & Anat., Niigata University Graduate 

School of Medical and Dental Sciences, Niigata, Niigata, Japan; 

3Physiology, Virginia Commonwealth University, Richmond, VA 

Methods used to study degeneration and regeneration in the 

vomeronasal system typically result in collateral damage to olfactory 

system pathways. We set out to develop a new approach to selectively 

lesion the vomeronasal nerves and to leave the olfactory system and its 

nerve fibers intact. For this study we used OMP-tauLacZ mice and Xgal 

staining, which allowed us to label both vomeronasal and olfactory 

pathways containing the Olfactory Marker Protein (OMP). Vannis 

micro-dissecting scissors were used to cut the vomeronasal nerves at a 

point just anterior to the Accessory Olfactory Bulb (AOB). We then 

observed the vomeronasal epithelium, the olfactory epithelium, the 

main olfactory bulb (MOB) and the AOB at 1, 6, 20, 60 and 120 days 

after nerve lesion. At days 20 and 60 we found that there were no OMP 

positive cells in the vomeronasal epithelium and no OMP positive nerve 

terminals in the AOB. In contrast, OMP positive cells in the olfactory 

epithelium and their OMP positive nerve fiber projections to the MOB 

remained intact. In a few animals examined after 120 days of recovery 

we noticed OMP staining in both the vomeronasal epithelium and 

nerve projections within the AOB. These findings suggest that recovery 

in the vomeronasal epithelium may be associated with the retargeting of 

nerve fibers in the AOB. This new approach to vomeronasal nerve 

transaction may prove important for behavioral studies of vomeronasal 

function, since it has the distinct advantage of leaving the olfactory 

system intact. Supported by NIH grant DC00165. 

42 Slide [ ] Vomeronasal Organ 

PROTEOMICS ANALYSIS OF OLFACTORY SYSTEMS: A 

GENERIC APPROACH USING DIFFERENTIAL DYE 

ANALYSIS AND DE NOVO PEPTIDE SEQUENCING FOR 

IDENTIFYING PROTEINS POTENTIALLY INVOLVED IN 

PHEROMONE TRANSPORT AND RECEPTION. 

Greenwood D. 1, Jordan M. 1, Cooney J. 2, Jensen D. 2, Plummer K. 3, 

Newcomb R. 1, Rasmussen L. 4 1Gene Technologies, HortResearch, 

Auckland, New Zealand; 2HortResearch, Hamilton, New Zealand; 

3School of Biological Sciences, University of Auckland, Auckland, New 

Zealand; 4Oregon Graduate Institute of Science & Technology, 

Beaverton, OR 

Mucosal proteins from the trunk and VNO duct of the Asian elephant 

and proteins, both soluble and membrane-bound, extracted from the 

antennae of tortricid moths have provided us with diverse sources of 

olfactory proteins. We have developed a proteomics platform which 

concentrates on targeting proteins that are differentially expressed, such 

as exhibiting sex-specific expression. This approach enables us to 

significantly reduce the total number of proteins that feed into our 

proteomics pipeline. Proteins conjugated from reaction with 

multiplexed fluorescent dyes are separated on 1-D and 2-D 

polyacrylamide gels and scanned at segregating wavelengths. The 

resultant images are processed using gel analysis software. Those 

proteins displaying significantly altered levels or in a new position are 

excised and subjected to trypsin hydrolysis and released peptides are 

analyzed by nanoelectrospray ion-trap mass spectrometry. Primary data 

crunching is performed using peptide search algorithms interrogating 

both public domain and proprietary databases. Emphasis is placed on 

data generated from de novo sequencing of peptides using the 

DeNovoX® package followed by BLAST analysis in an attempt to 

overcome the shortfall of having incompletely sequenced genomes. 

11 

43 Poster [ ] Olfactory Transduction 

G-PROTEINS IN ANOPHELES GAMBIAE OLFACTION 

Rützler M. 1, Zwiebel L. 1 1Biological Sciences, Vanderbilt University, 

Nashville, TN 

Chemoreception in general and olfaction in particular represent 

critical sensory inputs into many behaviors of hematophagous (bloodfeeding) 

insects. Recently the first odorant receptors (ORs) of the 

malaria vector mosquito Anopheles gambiae (AgORs) have been 

identified and functionally characterized. In addition to these studies, it 

will be important to develop methodology to facilitate high throughput 

screening of substances, which could potentially lead to the 

development of a new generation of efficient insect repellents. To build 

an experimental setup that could allow such an approach, expansion of 

our current knowledge about signal transduction in insect olfaction is 

crucial. The current study identifies 6 genes in the Anopheles gambiae 

genome that encode G-protein (α-subunit) homologues. We have 

investigated tissue-specific expression of these Gα-genes and describe 

the expression pattern of a total of 11 transcripts in the adult mosquito. 

Furthermore we localized Gα-proteins within the female mosquitoantenna 

and identify candidates for Gα-proteins involved in olfactory 

signal transduction. Supported by grants from NIAID and NIDCD. 


THE NOVEL GUANYLYL CYCLASE MSGC-I MAY MEDIATE 

PHEROMONE-INDUCED CGMP IN THE ANTENNAE OF 

MANDUCA SEXTA 

Fernando S. 1, Collmann C. 2, Nighorn A. 1 1ARLDN, University of 

Arizona, Tucson, AZ; 2Neurobiology, University of Arizona, Tucson, AZ 

The signal transduction cascade induced by pheromone detection 

results in a transient increase in calcium followed by a slow increase in 

cGMP, which is thought to play a role in adaptation in the olfactory 

receptor neurons (ORNs) of Manduca sexta. However, the specific 

mechanism mediating this increase in cGMP is unknown. We wanted to 

determine if the novel guanylyl cyclase, MsGC-I, mediates this increase 

in cGMP. Using immunocytochemistry and in situ hybridization, we 

found that MsGC-I is likely to be expressed in at least a subset of 

pheromone-sensitive ORNs. Some neuronal calcium sensor (NCS) 

proteins are known to regulate calcium-dependent guanylyl cyclase 

activity in the olfactory system. To learn how the activity of MsGC-I 

might be regulated we are testing if MsFrequenin and/or 

MsNeurocalcin, two NCSs cloned previously and known to be 

expressed in ORNs, may mediate calcium-dependent regulation of 

MsGC-I activity. Supported by NIH-NIDCD DC04292

45 Slide [ ] Olfactory Transduction 

EVIDENCE FOR ALTERNATE TRANSDUCTION PATHWAYS 

IN THE MOUSE: OLFACTION IN THE CNGA2 KNOCKOUT 

Restrepo D. 1, Lin W. 1, Arellano J. 1, Slotnick B. 2 1Cell and 

Developmental Biology, Neuroscience Program and Rocky Mountain 

Taste and Smell Center, University of Colorado Health Sciences 

Center, Denver, CO; 2Psychology, University of South Florida, Tampa, 

FL 

In mammals the adenosine 3´,5´-monophosphate (cAMP) pathway is 

widely believed to be the only transduction mechanism in the main 

olfactory epithelium largely due to the lack of odor responsiveness of 

mice defective for cAMP signaling. Here we report on odor 

responsiveness in mice with a disrupted cyclic nucleotide gated (CNG) 

channel subunit A2. Several odorants, including putative pheromones, 

can be detected and discriminated by these mice behaviorally. These 

odors elicit electro-olfactogram (EOG) responses in the olfactory 

epithelium and activate a subset of glomeruli in the main olfactory bulb 

and stimulate neurons in of CNGA2 knockout mice. In addition, EOG 

responses to odors detected by CNGA2 knockout mice are relatively 

insensitive to inhibitors of the cAMP pathway. These results provide 

strong evidence that cAMP-independent pathways in the main olfactory 

system of mammals participate in detecting a subset of odors. 

This work was supported by NIH grants DC00566, DC04657, 

DC006070 (DR) DC0043 (WL) and MH6118 (BS). 


IDENTIFICATION OF THE SECOND MESSENGER THAT 

MEDIATES SIGNAL TRANSDUCTION IN THE NEWT 

OLFACTORY RECEPTOR CELL 

Takeuchi H. 1, Kurahashi T. 1 1Frontier Biosciences, Osaka University, 

Osaka, Japan 

It has long been believed that vertebrate olfactory signal transduction 

is mediated by independent multiple pathways (utilizing cAMP and IP3 

as second messengers). However, the dual presence of parallel 

pathways in the olfactory cilia is still controversial, mainly because of 

the lack of information regarding the single cell response induced by 

odorants that have been shown to produce IP3 exclusively. 

In the present study, we examined two series of experiments. First, 

we compared responses induced by both cAMP- and IP3-odorants. 

Fundamental properties of responses were surprisingly homologous in 

spatial distribution of the sensitivity, waveforms, I-V relation and 

reversal potential, dose-dependence, time integration of stimulus, 

adaptation and recovery. By applying both types of odorants 

alternatively to the same cell, we observed cells to exhibit perfect 

symmetrical cross-adaptation. Second series of experiments was that 

the cytoplasmic cNMP concentration was manipulated through the 

photolysis of caged compounds to examine their real-time interactions 

with IP3-odorant-induced events. The Properties of responses induced 

by both IP3-odorants and cytoplasmic cNMP resembled each other in 

their unique characteristics. They showed symmetrical adaptation that is 

dependent on the Ca2+-infux. Furthermore, both responses were 

additive in a manner as predicted quantitatively by the theory that signal 

transduction is mediated by the increase in cytoplasmic cAMP. The 

data will provide evidence showing that olfactory responses are 

generated by a uniform mechanism for a wide variety of odorants. 

12 


PHARMACOLOGICAL PROPERTIES OF A POSSIBLE TRP- 

RELATED ION CHANNEL IN LOBSTER OLFACTORY 

RECEPTOR NEURONS 

Bobkov Y.V. 1, Ache B.W. 1 1The Whitney Laboratory, Center for Smell 

and Taste, McKnight Brain Institute, University of Florida, Gainesville, 

FL 

Lobster olfactory receptor neurons express a sodium-gated nonselective 

cation channel (Zhainazarov et al., J. Neurophysiol.79:1349, 

1998) that is a potential member of the growing family of trp channels. 

Here, we extend our pharmacological characterization of the channel by 

recording the effect of potential agonists and antagonists on the channel 

in cell-free patches. In addition to Na + , the channel is activated by Ca2+ , 

PIP2, PIP3, and maitotoxin, and antagonized by H + , calmodulin 

inhibitors, and the trp channel blockers 2APB, SKF96365, ruthenium 

red, Al3+ , Gd3+ , and La3+ . Interestingly, decreasing extracellular pH 

from 8.0 to 7.5, a range in which pH is not known to block other ion 

channels, effectively blocked the lobster channel and could serve as a 

selective probe for the channel. We are in the process of using this 

enhanced pharmacological profile to implicate the channel as a target of 

odor-activated phosphoinositide signaling in the cells. Supported by the 

NIDCD (DC01655). 


EXPRESSION OF TRP CHANNELS AND ODORANT 

RECEPTOR SIGNALING IN ODORA CELLS 

Liu G. 1, Talamo B.R. 1 1Neuroscience, Tufts University, Boston, MA 

To examine signaling pathways directly activated by odorant 

receptor, we utilize the olfactory epithelial cell line, Odora. Odora cells 

functionally express transfected odorant receptor U131 without 

requiring concurrent transfection of additional signaling proteins 

(Murrell and Hunter, 1999). Previously we showed that Odora cells 

express adenylyl cyclase III, phospholipase C isoforms, and G proteins 

found in the olfactory epithelium (OE). Cai signals in Odora cells are 

not activated by the canonical cAMP cascade; transfected U131 

receptors in Odora cells activate PLC, IP3 and IP3 receptor to elevate 

Cai without the release of intracellular Ca2+. Biotinylation studies 

reveal that there is cell surface expression of IP3 receptors I-III in 

Odora cells, implicating one or more IP3 receptors as a possible route 

for Ca2+ entry mediated by odorant. In this study, we explore the 

expression of transient receptor potential (TRP) channels to assess the 

possibility that they might participate in odor-activated Ca2+ entry 

through the plasma membrane. RT-PCR analysis of all 7 mammalian 

TRPC channels reveals transcripts for TRPC1 and TRPC5 in both 

Odora cells and nasal epithelium. Western blotting further documents 

the expression of protein for TRPC5, but not for TRPC1. Current 

studies using antibodies to TRPC5 and TRPC1 examine the localization 

of TRPCs in the rat olfactory system. These observations continue the 

characterization and evaluation of a unique pathway activated by 

odorant receptor in Odora cells that may reveal an important role for 

alternative signaling through the odorant receptor in the olfactory 

system in vivo. Supported in part by DC 05229-01A1.


ODOR-INDUCED CALCIUM RESPONSES FROM SQUID 

OLFACTORY RECEPTOR NEURONS 

Sitthichai A.A. 1, Lucero M.T. 1 1Physiology, University of Utah, Salt 

Lake City, UT 

ORNs from the squid Lolliguncula brevis fall into 5 morphological 

subtypes. Previously we characterized odor responses in 2 

morphological subtypes from isolated squid olfactory receptor neurons 

(ORNs) 1 . Because the isolation process destroys the other 3 subtypes, 

we have developed a slice preparation to make physiological recordings 

from a relatively intact olfactory epithelium. Thus far, 

electrophysiological recordings from slices have been challenging 

because of the thick mucous that covers the olfactory organ. Initial 

Ca2+ imaging studies using the fluorescent Ca2+ indicator dye, Fluo-4, 

and laser scanning confocal microscopy were unsuccessful because the 

tissue underlying the olfactory epithelium spontaneously contracts after 

dissection from the animal. We tested numerous receptor antagonists, 

ion channel inhibitors and conotoxins that were unsuccessful in 

blocking spontaneous contractions. Both isotonic MgCl and 62.5 

2 

µg/ml ketamine blocked the tissue contractions but also inhibited odorinduced 

Ca2+ responses. Fortunately, we found that 5 µM nicotine 

completely blocks spontaneous contractions without compromising 

odor responses. We are currently using the squid olfactory organ slice 

preparation to test the odor specificity and transduction pathway of the 

5 morphological subtypes of ORNs. Application of this methodology 

will allow us to correlate morphology, odor specificity and signal 

transduction in real time across a relatively intact olfactory epithelium. 

Funded by NINDS NS07938 (MTL) and NIDCD DC006793 (AAS). 

1. M. T. Lucero, F. T. Horrigan, and W. F. Gilly. J.Exp.Biol. 162:231- 

249, 1992. 


NOVEL ACTION OF CALMODULIN ON NATIVE RAT 

OLFACTORY CNG CHANNELS 

Bradley J. 1, Bönigk W. 2, Gensch T. 2, Yau K. 1, Kaupp B. 2, Frings S. 3 

1Department of Neuroscience/HHMI, Johns Hopkins University, 

Baltimore, MD; 2IBI-1, Forschungszentrum, Jülich, Germany; 

3Molecular Physiology, University of Heidelberg, Heidelberg, Germany 

Adaptation to stimuli is an important process in sensory neurons. In 

vertebrate olfactory receptor neurons, rapid negative-feedback 

inhibition of Ca2+-permeable, cAMP-gated (CNG) transduction 

channels underlies adaptation. Previous studies with CNGA2, a CNG 

channel subunit that forms a homomeric channel when expressed 

heterologously, have implicated binding of Ca2+/calmodulin 

(Ca2+/CaM) to CNGA2 in adaptation. Native rat olfactory CNG 

channels, however, are a heteromeric complex of three homologous 

subunits, CNGA2, CNGA4 and CNGB1b. We now report that the 

CaM-binding site on CNGA2 does not mediate at all the modulation by 

Ca2+-CaM of native channels. We find that, with native channels in 

resting neurons, Ca2+-free calmodulin (apocalmodulin) is largely preassociated. 

Accordingly, apocalmodulin-binding sites of the IQ-type are 

together necessary and sufficient for Ca2+/CaM feedback inhibition of 

heteromeric channels. Thus, calmodulin is permanently associated with 

native channels in ORNs, poised at the site of Ca2+ influx as a Ca2+ 

sensor to rapidly effect inhibition. Apart from mechanistically 

explaining the fast kinetics of adaptation to odorants, our findings 

caution against the practice of extrapolating findings from 

heterologously expressed homomeric channels to native heteromeric 

channels. 

13 


AMPLIFICATION BY A SINGLE GPCR MOLECULE IN THE 

OLFACTORY RECEPTOR NEURON 

Bhandawat V. 1, Reisert J. 2, Yau K. 3 1Neuroscience, Johns Hopkins 

University, Baltimore, MD; 2Howard Hughes Medical Institute, 

Baltimore, MD; 3Neuroscience (HHMI), Johns Hopkins University, 

Baltimore, MD 

Odorants bind to specific G-protein coupled receptors (GPCRs) on 

olfactory neurons, which, via a G-protein cascade, convert chemical 

signals into an electrical response. We have measured membrane 

current from single frog (Rana pipiens) olfactory neurons and analyzed 

the odorant-receptor interaction. We find that an odorant molecule 

rapidly unbinds from the receptor, often before the activation of a Gprotein. 

This leads to low amplification between receptor activation and 

G-protein activation, which is confirmed by the small size of the unitary 

event as derived by quantal analysis. Although the individual events are 

very small, there is a non-linear summation of these events that 

amplifies the response greatly. Funded by Howard Hughes Medical 

Institute. 

52 Slide [ ] Olfaction: Animal Behavior 

A COMPARISON OF SENSORY HAIR DISTRIBUTION ON 

THE CHELAE AND OLFACTORY ORGANS OF CRAYFISH 

(ORCONECTES RUSTICUS) 

Bergman D.A. 1, Belanger R.M. 1, Moore P.A. 1 1Biological Sciences, 

Bowling Green State University, Bowling Green, OH 

Sensory hairs are found in great abundance on the appendages of 

crayfish and have been shown to be important for detecting both 

mechano- and chemosensory stimuli. Detailed analysis of the spatial 

distribution of these sensory hairs that is correlated with sex or 

reproductive forms allows us to determine if a particular sensory hair 

type or abundance could be important for mating. With this in mind, we 

examined the sensory hair distribution of form I (reproductive) and 

form II (non-reproductive) males, as well as females using scanning 

electron microscopy. We quantified and qualified all sensory hair types. 

Our research indicates that reproductive male crayfish have a greater 

number of feathered hairs on their chelae and antennules when 

compared to non-reproductive males and females. This increase in 

sensory hair distribution suggests a link between sensory hairs and 

mating chemical cues in the crayfish. Male and female crayfish have 

different distributions and abundance of sensory hairs on the sensory 

appendages. These differences are likely a function of the different 

reproductive life histories where males actively pursue and locate 

females. In all, the sensory hairs on all of the appendages appear to be 

important in mate recognition.

53 Poster [ ] Olfaction: Animal Behavior 

AESTHETASCS, THE OLFACTORY SENSILLA, ARE 

MEDIATORS OF CHEMOSENSORY ACTIVATION OF 

ANTENNULAR FLICKING IN THE SPINY LOBSTER, 

PANULIRUS ARGUS 

Daniel P.C. 1 1Biology, Hofstra University, Hempstead, NY 

Lobster antennules bear a number of different sensilla sensitive to 

odorants. We have found that two antennular behaviors, grooming 

(Wroblewska et al., Chem. Senses 27:769-778, 2002) and flicking (Fox 

et al. Chem. Senses 28:555, 2003), are mediated by aesthetascs and/or 

asymmetric setae located in the “tuft” region of the lateral flagellum. 

Flicking also requires “non-tuft” setae scattered across the lateral and 

medial flagella. Schmidt et al. (this meeting) have found through 

ablation experiments that grooming is solely activated by asymmetric 

setae. The present study used similar techniques to determine the 

relative importance of aesthetascs and asymmetric setae to activation of 

flicking behavior. Two groups of lobsters were sham-ablated by 

removing a row of guard setae and then tested for antennular responses 

to L-glutamate (the major chemical stimulus eliciting grooming), and 

squid extract (concentration). This was followed by either ablation of 

asymmetric setae (N=8) or ablation of aesthetascs (N=6) after which the 

behavioral assay was repeated. Lobsters with asymmetric setae 

removed no longer groomed in response to glutamate but showed no 

reduction in flick rate to squid extract compared to their responses to 

the same odorants following sham ablation. In contrast, lobsters with 

aesthetascs removed showed no reduction in grooming to glutamate but 

no longer increased flick rates to squid extract. These results, along 

with those from the earlier study, suggest that olfactory and 

nonolfactory pathways are utilized in eliciting flicking behavior in 

which processing occurs via the olfactory lobes and the lateral 

antennular neuropils. 


BEHAVIORAL DISCRIMINATION OF AMINO ACIDS IN 

ZEBRAFISH (DANIO RERIO) 

Valentincic T. 1, Miklavc P. 1 1Department of Biology, University of 

Ljubljana, Ljubljana, Slovenia 

Based on the dissimilar patterns of glomerular activation during 

amino acid stimulation in recent calcium-imaging studies in zebrafish 

(Friedrich and Korsching, 1997), it is possible, but previously untested, 

that this species is capable of discriminating behaviorally different 

amino acids. As performed in catfish, olfactory discrimination was 

studied by conditioning zebrafish with a food reward that was presented 

90 seconds after the conditioning amino acid solution was injected into 

the aquarium. Tests for discrimination began after ~50 conditioning 

sessions. Conditioned zebrafish, which associated a specific amino acid 

odor with a food reward, searched for food longer and more intensely 

(measurements of the swimming path by video-tracking or counting the 

turns >90 degrees during 90 seconds) than after stimulation with a nonconditioned 

amino acid. We used 3x10-5M L-Ala, L-Val and L-Arg, 

respectively, as conditioning stimuli and the following as test stimuli: 

Gly, L-Ala, L-Ser, L-Phe, L-Tyr, L-Trp, L-His, L-Asn, L-Val, L-Ile, L- 

Leu, L-Met, L-Arg, L-Lys, L-Glu, L-Asp, L-Pro and D-Ala . With the 

exception of the L-Val conditioning stimulus and the L-Ile test 

stimulus, zebrafish discriminated all the conditioning stimuli from the 

test stimuli. Our results clearly indicated that the amino acids that 

previously showed similar glomerular activity patterns (e.g. L-Val and 

L-Ile), were not discriminated behaviorally by zebrafish, but those in 

which the glomerular activation patterns were distinct were readily 

discriminated. 

Friedrich, R.W. and Korsching, S., 1997. Combinatorial and 

chemotopic odorant coding in the zebrafish olfactory bulb visualised by 

optical imaging. Neuron 18:737-752. 

14 


OLFACTORY COMMUNICATION: EVOLVING NEW BLENDS 

AND NOVEL PREFERENCES 

Vickers N.J. 1, Hillier K. 1, Groot A. 2, Gould F.L. 2 1Biology, University 

of Utah, Salt Lake City, UT; 2Entomology, North Carolina State 

University, Raleigh, NC 

Male moths are often extremely sensitive and narrowly tuned to the 

blend of components emitted by conspecific females. The sexual 

communication channel is therefore under strong stabilizing selective 

pressure. How then do new female blends and male preferences evolve? 

Two closely related moth species, Heliothis virescens and Heliothis 

subflexa, can be hybridized under laboratory conditions in order to 

study the genetic basis of behavior and olfactory characteristics that 

accompany species divergence. Males of these two species prefer 

qualitatively distinct blends that include either Z9-14:Ald (H. virescens) 

or Z9-16:Ald (H. subflexa). In addition, H. subflexa males require Z11- 

16:OH. These behavioral preferences are correlated with the specificity 

of olfactory receptor neurons and central interneurons arborizing within 

the glomeruli of the male-specific macroglomerular complex. Wind 

tunnel studies have shown that Z9-14:Ald/Z9-16:Ald preference 

segregates in a 1:1 ratio in backcross males. Preliminary genetic (QTL) 

analyses have revealed that this trait is associated with a single 

autosomal chromosome suggesting that a major gene may control this 

phenotype, perhaps coupled to the expression of odorant receptors. 

Other divergent characters in this system, such as Z11-16:OH-agonism 

and Z11-16:OAc-antagonism, may involve odorant receptors but also 

likely involve shifts in the glomerular targets of receptor axons and 

interpretation of olfactory information by higher brain centers. 

Supported by NSF IBN-9905683 to NJV. 


OLFACTORY RECOGNITION IN CANINES 

Puchalski D. 1, Leitch A. 1, Hornung D. 1 1Biology Department, St. 

Lawrence University, Canton, NY 

The overall objective of this work was to assess the specificity of the 

olfactory cues that canines use when identifying humans. That is, once 

a dog is trained to identify the smell of a human (the target), will the 

dog be confused by the smell of the target´s siblings or by the smell of 

other people who use the target´s soap or deodorant? A 1-year-old 

golden retriever was trained to pick her owner´s scent out of three 

possible choices. After a trial had been initiated by “go” the dog would 

smell each of three boxes containing T-shirts impregnated with human 

scent. The target was randomly assigned to one of the boxes. The boxes 

were constructed such that the dog could not use visual cues. The dog 

signaled recognition of the target´s smell by a sit/stay response. The 

dog was trained to correctly identify the target over 90% of the time. 

When there was no target present the dog would repeatedly sample the 

three boxes and 80% of the time give no recognition signal. The dog 

was rewarded only for correct target responses. Probe trials consisting 

of the scent of the target´s siblings or of the scent of other humans who 

had used the soap and/or deodorant of the target were inserted into the 

testing sessions. There was no reward given during a probe trial. The 

dog gave the recognition response more often to the smell of the 

target´s siblings as compared to the smell of non-related humans. 

Likewise the dog gave the recognition response more often when nonrelated 

humans used either the soap or deodorant of the target. These 

results suggest that both genetic factors (such as HLA typing) and 

added smells (such as soap) may have some bearing on canine olfactory 

recognition of humans.


MLPEST AS A MEASURE OF OLFACTORY SENSITIVITY 

THRESHOLD IN MICE 

Clevenger A.C. 1, Restrepo D. 1 1Cell and Developmental Biology, 

University of Colorado Health Sciences Center, Denver, CO 

Threshold is defined as the stimulus intensity necessary for a subject 

to reach a specified percent correct on a detection test. Unfortunately, 

many measures of threshold in sensory systems are heavily influenced 

by decision making processes and are subject to extinction. MLPEST 

(Maximum-Likelihood Parameter Estimation by Sequential Testing) is 

a method that minimizes both decision-based bias and extinction. 

Originally developed for human auditory and visual tasks, it has been 

also been utilized for human olfactory and gustatory tests. Indeed, a 

recent comparison of MLPEST with other methods to test olfactory and 

gustatory thresholds demonstrated reliable and precise threshold 

measurements (Linschoten et al. Percept. Psychophys. 63:1330, 2001). 

However, this comparison was limited to its application for human 

subjects. In order to modify this technique for olfactory testing in mice, 

we have adapted MLPEST methodology to the computerized 

olfactometer of Bodyak and Slotnick (Chem. Senses 24:637, 1999). 

Here we present data that demonstrate the utility of this technique in 

mice, and we discuss the ramifications of altering MLPEST test 

parameters on performance. 

This work was supported by NIH grants DC00566, DC04657 (DR) 

and F30 DC 5740 (AC). 


VIRUS-INDUCED BODY ODORS IN MICE 

Beauchamp G.K. 1, Ross S.R. 2, Curran M. 1, Hultine S. 2, Yamazaki K. 1 

1Monell Chemical Senses Center, Philadelphia, PA; 2Department of 

Microbiology, University of Pennsylvania, Philadelphia, PA 

Mouse Mammary Tumor Virus (MMTV) provides an attractive 

animal model to study the effects of infection on body odor. MMTV is 

a retrovirus that either is passed from mother to offspring through her 

milk or is transmitted genetically as an endogenous provirus. 

Depending on the mouse strain, multiparous infected females often 

develop mammary tumors. The provirus genome consists of several 

genes one of which, Sag codes for a superantigen that is presented by 

MHC Class II on B cells and acts to delete specific subsets of T cells in 

the host. We previously demonstrated that mice infected by MMTV by 

suckling on infected dams expressed a distinctive odor as shown by the 

ability of trained mice to discriminate odors of infected vs. non-infected 

controls in a Y maze. Endogenously expressed MMTV can be used to 

investigate mechanisms of body odor change. In the first study with 

endogenous virus, we found that mice transgenic for an MMTV 

provirus (C3H/HeN) express a different odor than control littermates. 

In the second study, we demonstrated that mice differing from control 

littermates only by expressing the Sag gene (MMTV-ORF 16) also had 

a distinctive body odor. This result suggests that changes in immune 

function, likely alterations in the T-cell repertoire, underlie body odor 

changes following MMTV infection. Variations in immune function 

following infection may thus result in specific volatile signals useful in 

disease diagnosis. 

Supported by NSF Grant#0112528 

15 


OLFACTORY FEAR CONDITIONING AND DISCRIMINATION 

IN MICE. 

Jones S.V. 1, Heldt S. 1, Davis M. 1, Ressler K.J. 1 1Center for Behavioral 

Neuroscience, Emory University, Atlanta, GA 

A method for producing long-lasting olfactory learning and 

discrimination within a single session is required for future studies of 

the molecular bases of olfactory memory. In previous studies, we have 

shown that mice can learn olfactory-cued fear as measured by both 

freezing and fear potentiated startle, the two most common fear 

measures in rodents. We first show that mice have enhanced fear 

potentiated startle and freezing after pairing odors with footshocks in a 

paradigm that supports learning, but not when the same number of 

odors and shock presentations are presented in an unpaired fashion. 

Here we also show that mice can discriminate between an odor paired 

with a shock versus an unpaired odor. Using 10% amyl acetate or 5% 

acetophenone, we examined the unconditioned startle and freezing 

responses of mice prior to training. During training mice received five 

presentations of one odor alone interspersed with five pairings of the 

other odor with a footshock. The following day, we tested fear 

potentiated startle and freezing to these odors. Acoustic startle to the 

untrained odor and the trained odor were non-significant before 

training. After conditioning, the fear potentiated startle response to the 

untrained (8%) and trained (29%) odor were significantly different 

(p=0.002). Additionally, freezing prior to training was non-significant, 

but after training, mice froze significantly more to the conditioned odor 

(p=0.03). Ongoing studies investigating the role of the amygdala in 

these behaviors will pave the way for examining the molecular 

mechanisms of amygdala-dependent modulation of olfactory learning. 


OPPOSING EFFECTS OF D1 AND D2 RECEPTOR 

ACTIVATION ON ODOR DISCRIMINATION LEARNING 

Mcnamara A. 1, Yue E. 1, Cleland T. 2, Linster C. 3 1Neurobiology and 

Behavior, Cornell University, Ithaca, NY; 2Neurobiology and Nehavior, 

Cornell University, Ithaca, NY; 3Cornell University*, Ithaca, NY 

Dopaminergic modulation of cortical activity has been implicated in 

the planning, initiation, and control of movements, as well as in 

emotional responses, motivation, and the formation of reward 

associations. Additionally, there is abundant evidence for 

dopaminergic effects on olfactory processing, and in particular for the 

effects of dopaminergic modulation on odor detection thresholds. 

Using a simultaneous olfactory discrimination task, we here show that 

both D1 and D2 dopamine receptors can regulate rats´ olfactory 

discrimination capacities, and furthermore that the effects of D1 and D2 

receptor activation functionally oppose one another in the performance 

of this task. Specifically, injection of either the D1 agonist SKF 38393 

(10 mg/kg body weight) or the D2 antagonist spiperone (0.62 mg/kg) 

facilitated the difficult discrimination of similar odorants but had no 

effect on the easier discrimination of dissimilar odorants, whereas both 

the D1 antagonist SCH 23390 (0.025 mg/kg) and the D2 agonist 

quinpirole (0.2 mg/kg) significantly impaired rats´ ability to 

discriminate both similar and dissimilar odorants.


NOT ONLY - BUT ALSO -ADRENOCEPTORS ARE INVOLVED 

IN EARLY ODOR PREFERENCE LEARNING IN THE RAT 

Mclean J.H. 1, Mccann J. 2, Darby-King A. 1, Harley C.W. 2 1Basic 

Medical Sciences, Memorial University of Newfoundland, St. John's, 

Newfoundland, Canada; 2Psychology, Memorial University of 

Newfoundland, St. John's, Newfoundland, Canada 

Early preference olfactory learning is important for the survival of 

infant rats because they need to associate the odor of the mother with 

reward (food). In the neonate, tactile stimulation activates the locus 

coeruleus (Nakamura et al., 1987) in the brain stem. Noradrenergic 

(NE) neurons in the locus coeruleus (LC) have a strong axonal 

projection to the olfactory bulb (Shipley et al., 1985; McLean and 

Shipley, 1989; McLean et al., 1991). When NE activation is paired 

with odor in the neonate, preference for the odor (learning) takes place 

(Sullivan et al., 2000;Sullivan et al., 1991;Sullivan et al., 1989;Price et 

al., 1998;Langdon et al., 1997). The LC β-adrenergic input has been 

shown to be necessary and sufficient for preference acquisition to occur 

in rats up to around postnatal day 10. Surprisingly, despite observations 

that α-adrenoceptors are present (Day et al. 1997, Winzer Serhan et al, 

1997) and functional (Hayar et al. 2001) in the olfactory bulb, there is 

relatively little known about their function in behavior. In this study, we 

tested the hypothesis that α-adrenoceptors have roles similar to the βadrenoceptors 

in early olfactory learning. In this set of experiments we 

showed that activation of the α1-adrenoceptors was sufficient to induce 

early preference learning in the rat while the α2-adrenoceptor agonists 

did not show an effect. The α-adrenoceptors acted in a dose-dependent 

manner similar to the β-adrenoceptors in early odor preference learning. 

This work is supported by a grant from CIHR-CEDA Regional 

Partnership 


THE EFFECT OF CONCENTRATION AND CONDITIONING 

ON ODORANT DISCRIMINATION BY THE HONEYBEE 

Fussnecker B.L. 1, Carlton M. 1, Wright G. 2, Smith B.H. 1 1Entomology, 

Ohio State University, Columbus, OH; 2Mathematical Biosciences 

Institute, Ohio State University, columbus, OH 

Naturally occurring odors used by animals for mate recognition, food 

identification and other purposes must be detected at concentrations that 

vary across several orders of magnitude. Olfactory systems must 

therefore have the capacity to represent odors over a large range of 

concentrations regardless of dramatic changes in odor salience. The 

stability of the representation of an odor relative to other odors across 

concentration has not been extensively evaluated. We tested the ability 

of honeybees to discriminate pure odorants across a range of 

concentrations at and above their detection threshold. We also 

examined how their ability to discriminate among odors changed as a 

function of the number of times they had encountered an odorant in 

association with an appetitive reward. Our study showed that 

discrimination among odorants was a function both of the concentration 

and the number of experiences a subject has with an odorant. We 

hypothesize that this arises from two separate mechanisms in the 

olfactory system. 

16 


DILTIAZEM ADMINISTERED NASALLY DECREASES FOOD 

INTAKE AND ATTENUATES WEIGHT GAIN IN RATS 

Maher T.J. 1, Amer A. 1, Adams C. 2, Chen W. 3, Weinrich K. 3 

1Massachusetts College of Pharmacy and Health Sciences, Boston, MA; 

2Compellis Pharmaceuticals, Somerville, MA; 3Longwood 

Pharmaceuticals, Inc., Boston, MA 

Energy intake is continuously influenced by many complex 

endogenous neurochemical systems located both centrally and 

peripherally, in addition to numerous external environmental stimuli, 

such as olfaction. As the processing of odorant information by many 

olfactory neurons is mediated via Ca2+-currents through Ca2+ 

channels, a novel approach at influencing the ingestive behaviors of 

animals might therefore involve altering olfactory acuity via Ca2+ 

channel blockade. The present study tested the ability of a Ca2+ 

channel blocker, diltiazem (D), to alter food intake in rats made 

hyperphagic. D was delivered using the intranasal (i.n.), intraperitoneal 

(i.p.) and oral (p.o.) routes of administration. Male Sprague Dawley rats 

maintained in a reversed-lighting environment, which had been fooddeprived 

for 4hrs at the beginning of the dark cycle, were administered 

different doses of D or vehicle (V) and the amount of food consumed 

was measured. While food intake at 1, 2 and 4 hrs post D administration 

was significantly decreased in a dose-dependent manner after i.n. 

administration, neither the i.p. nor p.o. routes significantly affected food 

intake. In another experiment, rats were trained to eat their daily meal 

during the first 4hrs at the onset of the dark cycle. Once acclimated to 

this schedule, daily treatment for 14 days with i.n. D or V prior to food 

introduction resulted in a dose-dependent attenuation of weight gain. 

Together these studies suggest that i.n. administration of D possesses 

significant anorectic activity that may have utility in influencing energy 

intake. Additional studies are needed to determine the exact 

mechanisms and sites of action of i.n. administered D. 


KV1.3-TARGETED GENE-DELETION INCREASES 

METABOLIC FUNCTION AND OLFACTORY ABILITY 

Thompson R.N. 1, Perkins R.M. 1, Parsons A.D. 2, Overton M. 2, Fadool 

D. 1 1Dept. Biological Sci, Prog. in Neurosci., Florida State University, 

Tallahassee, FL; 2Dept Nutrition, Food, & Exer Sci, Prog. in Neurosci., 


Mice with gene-targeted deletion (KO) of the voltage-dependent K 

channel, Kv1.3, have smaller glomeruli and thus were behaviorally 

phenotyped to understand the channel´s contribution to olfaction. Mice 

were monitored (8d) in environmental chambers where data are 

computer-acquired every 30 seconds. KO animals were found to have 

abnormal ingestive behaviors yet equivalent daily caloric/water intake; 

KOs ate more intermittently and drank larger volumes less frequently. 

KO animals had slightly increased metabolism and locomotor activity 

in the dark cycle and weighed less than aged-matched wildtype mice. 

KO mice were not anosmic, in fact, retrieval time to recover a hidden 

food item was twice as fast as that observed for wildtype mice. Odor 

habituation trials using complex mixtures and single alcohols indicated 

that KO mice can discriminate molecules differing by only 1 carbon. 

Food-restricted mice were trained to dig for a hidden reward paired 

with an odorant using a two-choice paradigm to determine odorant 

threshold ability. KO mice performed the paired task more quickly and 

at concentrations 1,000 to 10,000 fold less than that by wildtype mice. 

While these tasks are influenced by memory, both genotypes performed 

equivalently in object recognition testing and test of motivation for 

object exploration. This unusual set of behaviors in the Kv1.3 KO mice 

suggest that Kv1.3 serves additional roles beyond shaping the resting 

potential. Supported by NIH DC03387(NIDCD) and NIH HL-56732.

65 Slide [ ] Trigeminal Chemoreception 

LINGUAL TACTILE ACUITY, TASTE PERCEPTION, AND 

THE DENSITY AND DIAMETER OF FUNGIFORM PAPILLAE 

IN FEMALE SUBJECTS 

Chopra A. 1, Essick G. 2, Guest S. 3, Mcglone F. 4 1Cognitive 

Neuroscience, Unilever R&D, UK, Merseyside, United Kingdom; 

2University of North Carolina at Chapel Hill, Chapel Hill, NC; 3Dental 

Research Centre, University of North Carolina at Chapel Hill, Chapel 

Hill, NC; 4Cognitive Neuroscience, Unilever R&D, Merseyside, United 

Kingdom 

A growing body of evidence suggests that individuals who differ in 

taste perception differ in lingual tactile perception. To address this 

issue, spatial resolution acuity was estimated for 83 young adult 

females (52 Asians and 31 Caucasians) by their ability to examine with 

the tongue and identify embossed letters of the alphabet. Ratings of the 

magnitude of the bitterness of 6-n-propylthiouracil (PROP) were 

obtained to characterize subjects' taste perception. The density and 

diameter of fungiform papillae on the anterior tongues of the Asian 

subjects were measured also. Subjects who rated the bitterness of PROP 

as very or intensely strong (supertasters) were found to be 25% more 

tactually acute than subjects who rated the bitterness as moderate to 

strong (medium tasters) and twice as acute as subjects who rated it as 

barely detectable or weak (non-tasters; P

69 Slide [ ] Trigeminal Chemoreception 

FATTY ACIDS INHIBIT DELAYED RECTIFYING K 

CHANNELS IN ISOLATED TRIGEMINAL NEURONS. 

Gilbertson T.A. 1, Klein J.T. 1, Farmer-George M. 1, Hansen D.R. 1, Simon 

S.A. 2 1Biology & Center for Integrated BioSystems, Utah State 

University, Logan, UT; 2Anesthesiology, Duke University, Durham, NC 

Chemosensory cues for fat have been shown to be mediated by fatty 

acids (FA) acting directly on subtypes of delayed rectifying K (DRK) 

channels in taste receptor cells (TRCs). Since it is generally believed 

that texture is important for oral fat recognition and that texture 

perception is mediated, at least in part, by trigeminal (TG) innervation, 

we have examined the effects of fatty acids (0.1-10 µM) on isolated rat 

TG neurons using whole-cell patch clamp recording. TG ganglia were 

removed and individual TG neurons were isolated by enzymatic 

methods and placed into culture for 24-72 h. Patch recordings were 

made before, during and after application of a variety of fatty acids 

including saturated (SFA), monounsaturated (MUFA) and 

polyunsaturated (PUFA) forms. Similar to our results in TRCs, PUFAs 

caused a reversible, time-dependent inhibition of DRK channels in TG 

neurons, consistent with an open-channel block leading to cell 

activation. In contrast to fungiform TRCs, which respond specifically to 

PUFAs, TG neurons were much less specific and responded to a variety 

of fatty acid types, including some MUFA and SFA, in a similar 

fashion. Thus, FA effects on DRK channels may not only mediate the 

taste of fat, but may also contribute to the perception of its textural 

properties via activation of oral TG fibers. Currently, we are using 

quantitative PCR to compare the expression of DRK channels in TG 

neurons with TRCs to determine the source of the FA specificity 

differences. Supported by NIH DK59611(TAG), DC01065 (SAS). 

70 Symposium [ ] Receptors: Choosing Genes, Targeting 

Axons, Detecting Chemicals 

PERCEPTION OF CHEMICAL CUES AND NAVIGATION IN C. 

ELEGANS 

Bargmann C.I. 1 1Anatomy, University of California, San Francisco, 

San Francisco, CA 

Behavior arises from the interplay between the environment and 

intrinsic properties of neurons and neural circuits. To understand how 

the genetics and development of the nervous system contribute to 

specific behaviors, we are studying olfactory system in the nematode C. 

elegans. C. elegans senses hundreds of different compounds, 

discriminates between them, and generates different behaviors in 

response to different odors. It is possible to define the specific neurons 

that generate these behaviors, since the C. elegans nervous system 

consists of just 302 neurons that have reproducible functions, 

morphologies and synaptic connections. Previous studies have 

generated an understanding of the methods by which animals detect and 

respond to a single sensory stimulus. In C. elegans, odors are detected 

by over 1000 G protein-coupled odorant receptors. Individual olfactory 

neurons express multiple receptor genes, allowing a few cells to detect 

many odors. A given sensory neuron is primarily dedicated to a single 

behavioral task, such as attraction or repulsion. We are now asking how 

animals navigate through complex sensory environments using multiple 

odors or sensory inputs. For these studies, we have focused on complex 

natural stimuli that should be present in the soil environment, such as 

different bacterial foods, natural physical stimuli, and other animals 

(social groups). C. elegans shows unexpected sophistication in its 

behavior when it faces ecologically relevant challenges like pathogenic 

bacteria or metabolic stress. Using the wiring diagram, we are 

identifying the circuits for navigation behavior and asking how sensory 

inputs regulate those circuits. 

18 



THE BIOLOGY OF SWEET, BITTER AND UMAMI TASTE 

Zuker C.S. 1 1Section of Neurobiology, University of California, San 

Diego, La Jolla, CA 



INTERNAL REPRESENTATIONS OF THE OLFACTORY 

WORLD 

Wang J. 1, Wong A.M. 2, Axel R. 3 1Neurobiology and Behavior, 

Columbia University, New York, NY; 2Department of Biochemistry and 

Molecular Biophysics, Columbia University, New YOrk, NY; 

3Biochemistry and Molecular Biophysics, Columbia University, New 

York, NY 

Olfactory perception requires the recognition of a vast repertoire of 

odorants in the periphery and central neural mechanisms that allow the 

discrimination of odors. The organization of the peripheral olfactory 

system appears remarkably similar in fruit flies and mammals. The 

convergence of like axons into discrete glomerular structures provides 

an anatomic map in the antennal lobe. How does the anatomic map 

translate into a functional map? We have developed a sensitive imaging 

system in the Drosophila brain that couples two-photon microscopy 

with the specific expression of the calcium-sensitive fluorescent 

protein, G-CaMP, to examine neural activity. At natural odor 

concentrations, each odor elicits a distinct and sparse pattern of activity 

that is conserved in different flies. We have combined Ca2+ imaging 

with electrical recordings to demonstrate the faithful propagation of the 

glomerular map by projection neurons that innervate the protocerebrum. 

The quality of an odor may therefore be reflected by defined spatial 

patterns of activity, first in the antennal lobe and ultimately in higher 

olfactory centers. We have identified a spatially invariant sensory map 

in the fly protocerebrum that is divergent and no longer exhibits the 

insular segregation of like axons observed in the antennal lobe. This 

organization provides the opportunity for the integration of multiple 

glomerular inputs by hierarchical cell assemblies in the protocerebrum.

73 Poster [ ] Salt and Sour Taste 

EXPRESSION OF THE AMILORIDE-SENSITIVE EPITHELIAL 

SODIUM CHANNEL IN THE MOUSE TASTE PAPILLAE 

Shigemura N. 1, Sadamitsu C. 2, Yasumatsu K. 1, Yoshida R. 1, Ninomiya 

Y. 1 1Section of Oral Neuroscience, Graduate school of Dental Science, 

Kyushu University, Fukuoka, Japan; 2Graduate School of 

Pharmaceutical Sciences, University of Tokyo, Tokyo, Japan 

It is proposed that amiliride-sensitive epithelial Na + Channels 

(ENaCs) are involved in taste signal transduction. Electrophysiological 

studies in C57 BL mice demonstrated that responses to NaCl are 

inhibited by amilolide in the choda tympani (CT) nerve but not in the 

glossopharyngeal (IXth) nerve, suggesting lack of amiloride sensitivity 

(AS) in the posterior tongue region innervated by IXth nerve. The AS 

also differs among inbred mouse strains. Judging from amiloride 

inhibition of NaCl responses of the CT nerve, the BALB strain showed 

very weak AS even in the anterior tongue. In this study, by using in situ 

hybridization (ISH) and semiquantitative RT-PCR techniques, we 

examined expression of three subunits of ENaC (alpha, beta, gamma) in 

the fungiform papillae (FP), circumvallate papilla (CP) and tongue 

epithelial tissue without taste papillae (ET) in C57BL and BALB mice. 

The results demonstrated that signals for alpha subunit of ENaC were 

clearly detected in some spindle-shape cells in both FP and CP, whereas 

those for beta and gamma subunits were clearly detected in some taste 

cells in FP, but only slightly in CP. In the ET, all three subunits were 

detected. These results together with those reported by previous studies 

suggest that expression patterns for the three subunits of ENaC may 

contribute to the tongue regional difference in AS in mice. With regard 

to the strain difference in AS, we are examining the gene polymorphism 

for each subunits of ENaC between C57BL and BALB strains by 

sequencing analysis. 


QUANTITATIVE PCR ANALYSIS OF THE ALDOSTERONE- 

REGULATED SALT TRANSDUCTION PATHWAY IN TASTE 

CELLS. 

Burks C.A. 1, Hansen D.R. 1, Gilbertson T.A. 1 1Biology & Center for 

Integrated BioSystems, Utah State University, Logan, UT 

Evidence suggests that sodium salt taste transduction pathways 

involving the epithelial sodium channel (ENaC) are responsive to 

aldosterone (ALDO) via its well-documented late genomic effects (12- 

48 h). Using RT-PCR, we previously identified a number of early (


AMILORIDE DISRUPTS NACL VS. KCL TASTE 

DISCRIMINATION IN INBRED MICE WHETHER THEIR 

CHORDA TYMPANI NERVES ARE AMILORIDE SENSITIVE 

OR NOT 

Eylam S. 1, Spector A.C. 1 1Department of Psychology and Center for 

Smell and Taste, University of Florida, Gainesville, FL 

In rodent taste bud cells, NaCl is transduced via one pathway 

selective for Na + and disrupted by the lingual application of the 

epithelial Na + channel blocker amiloride, and another less cationselective 

and amiloride-insensitive pathway(s). In rats, amiloride 

appears to render NaCl qualitatively indistinguishable from KCl in a 

dose-dependent fashion. In mice, amiloride has been shown to reduce 

chorda tympani (CT) responses to NaCl in some strains (e.g. C57BL/6J 

(B6)) but not others (e.g. 129, DBA/2 (D2) and BALB/c (BALB)). We 

used a two-response operant task to train mice from these 4 strains 

(7/strain) in a gustometer to discriminate between 5-lick samples of 

NaCl and KCl with concentration (0.1-1 M) varied to render intensity 

irrelevant. Unexpectedly, the overall performance of the B6 mice was 

significantly lower than that of the other strains. All mice were then 

tested with the stimuli adulterated with a descending order of amiloride 

concentrations (0.1-100 µM) with control sessions interposed. In all 4 

strains, overall performance dropped to chance at 100 µM amiloride 

and sigmoidally improved as the adulterating amiloride concentration 

was lowered. Performance on NaCl trials was much more affected than 

that on KCl trials. Thus, the ability to discriminate between NaCl and 

KCl depends on an amiloride-sensitive transduction pathway in the 4 

strains tested here. Possibly, D2, 129, and BALB (and perhaps B6) 

mice have amiloride-sensitive taste receptor cells innervated by 

gustatory nerves other than the CT. Supported by NIDCD R01- 

DC04574. 


SUPRATHRESHOLD INTENSITY DISCRIMINATION OF 

NACL IN RATS WITH CHORDA TYMPANI OR 

GLOSSOPHARYNGEAL NERVE TRANSECTION 

Colbert C.L. 1, Garcea M. 1, Spector A.C. 1 1Psychology Department and 

Center for Smell and Taste, University of Florida, Gainesville, FL 

In rats, chorda tympani nerve (CT) transection (CTX) but not 

glossopharyngeal nerve (GL) transection (GLX) raises NaCl taste 

detection threshold, but the effect of CTX or GLX on suprathreshold 

intensity discrimination is unknown. We examined whether CTX or 

GLX in male Sprague-Dawley rats would disrupt a presurgically trained 

NaCl intensity discrimination in a two-lever operant task. Thirsty rats 

were required to correctly press one lever in response to a standard 

concentration and the other lever in response to higher comparison 

concentrations for water reward. The hit rate for comparison stimuli 

was adjusted for the standard false alarm rate and a logistic function 

was fit to the concentration-performance data. The concentrations at the 

curve midpoints (c) were used to compare differential sensitivity across 

groups. The mean c for the CTX group (n=4) significantly differed 

from that for the sham-operated (SHAM; n=4) and GLX (n=3) groups 

postsurgically with a 0.05 M NaCl standard, though the magnitude of 

difference was only 0.16 log units. The corresponding Weber 

10 

Fractions (WF) were significantly higher in the CTX group (1.33) 

compared with the SHAM (.64) and GLX (.64) groups. In contrast, the 

cs nor WFs (CTX=.70; GLX=.67; SHAM=.49) significantly differed 

across groups when the standard was 0.1 M NaCl. These findings add 

to a growing list of taste-related behavior for which the GL is 

unnecessary, but the small effect of CTX on NaCl intensity 

discrimination is in contrast with its more striking effects on absolute 

detection. Supported by NIH R01-DC01628. 

20 


RELATIVE EFFECTS OF TRANSECTION OF THE 

GUSTATORY BRANCHES OF THE 7TH AND 9TH CRANIAL 

NERVES ON NACL DETECTABILITY IN RATS 

Blonde G.D. 1, Garcea M. 1, Spector A.C. 1 1Department of Psychology 

and Center for Smell and Taste, University of Florida, Gainesville, FL 

Chorda tympani nerve (CT) transection in rats severely impairs NaCl 

taste detection. Higher concentrations of NaCl are nonetheless 

detectable suggesting that the remaining gustatory nerves can maintain 

some degree of salt sensibility. We used a two-response operant taste 

detection task to presurgically train male Sprague-Dawley rats and 

measure NaCl sensitivity in a gustometer. A modified descending 

method of limits procedure was used in which a single concentration, 

pitted against water in a session, was progressively lowered across test 

days. Logistic functions based on overall percentage correct were 

derived. The concentrations at the curve midpoints (c) were used to 

compare NaCl sensitivity before and after sham surgery (SHAM, n=5), 

transection of both the CT and greater superficial petrosal nerve (GSP) 

(7X; n=6), or transection of the glossopharyngeal nerve (9th ) (9X, n=4). 

The value of c did not significantly change after surgery for the SHAM 

and 9X groups. In contrast, the 7X surgery significantly raised c by 

~2.50 log units, a shift greater than that reported for CT transection. 

10 

These rats were still able to detect very high concentrations suggesting 

that the 9th or superior laryngeal nerve might support NaCl detection at 

these stimulus intensities, although the role of trigeminal cues cannot be 

dismissed. Histology is currently underway. These results suggest that 

the GSP contributes to NaCl sensitivity in the rat and confirm the 

primacy of the 7th nerve relative to the 9th nerve in sensibility to NaCl. 

Supported by NIH R01-DC01628. 


ASIC2 IS NOT NECESSARY FOR SOUR TASTE IN MICE 

Richter T.A. 1, Dvoriantchikov G. 1, Chaudhari N. 2, Roper S.D. 2 

1Physiology & Biophysics, University of Miami School of Medicine, 

Miami, FL; 2Physiology & Biophysics and Program in Neuroscience, 

University of Miami School of Medicine, Miami, FL 

The acid-sensitive cation channel, ASIC2, is widely believed to be a 

receptor for acid (sour) taste in mammals, based on its physiological 

properties and expression in rat taste cells. Thus, we evaluated acid 

taste responses in wild type and ASIC2 knockout mice. Ca 2+ imaging 

experiments were carried out using confocal microscopy on slices of 

circumvallate papillae to which taste stimuli were applied focally at the 

taste pore. Surprisingly, taste cells from ASIC2 knockout mice 

exhibited normal physiological responses to 20-100mM citric acid. The 

incidence (number of acid-responsive cells) and response amplitude 

(increase in [Ca 2+ ]i) were identical across the two genotypes. Hence, we 

explored the expression pattern of the four channels, ASIC1-4, in taste 

buds from both rat and mouse. Using RT-PCR, we detected expression 

of ASIC1 and ASIC3, but not ASIC4, in mouse and rat taste buds and 

non-sensory lingual epithelium. Interestingly, we found that mRNA for 

ASIC2 is not expressed at significant levels in mouse taste buds, 

although we observed its robust expression in rat taste buds. Our results 

indicate that ASIC2 is not required for acid taste in mice. The findings 

also highlight that there may be important differences in taste 

transduction mechanisms between mice and rats. Supported by 

NIH/NIDCD grants 2RO1 DC00374 (SDR) and 1R21 DC5500 (NC).


COLD INHIBITS SOUR TASTE TRANSDUCTION 

Defazio R.A. 1, Richter T.A. 1, Roper S.D. 1 1Physiology and Biophysics, 

University of Miami, Miami, FL 

The taste transduction mechanism underlying sour taste remains to be 

elucidated. The basic mechanism is believed to be an acid-sensitive ion 

channel, the activation of which depolarizes the membrane potential. 

Membrane depolarization activates voltage-gated calcium channels 

(VGCCs) and allows Ca2+ influx, thereby increasing intracellular 

calcium ([Ca2+ ] ). Increased [Ca i 2+ ] presumably initiates 

i 

neurotransmitter release. Many ion channels, especially acid-gated 

channels, are sensitive to changes in temperature. Thus, we reasoned 

that the temperature sensitivity of sour taste transduction might provide 

clues to the identity of transduction channels in acid-responsive taste 

cells. We examined the effect of temperature on tastant-induced 

changes in [Ca2+ ] in mouse vallate taste cells using confocal 

i 

fluorescence microscopy and acutely prepared lingual slices. At 30°C, 

bath application of 100 mM KCl depolarized cells and activated 

VGCCs, resulting in increased [Ca2+ ] in a subpopulation of taste cells. 

i 

In a subset of these KCl-responsive cells, focal application of 100 mM 

citric acid produced robust increases in [Ca2+ ] . When the bath 

i 

temperature was lowered to 17°C, the response to citric acid was 

reduced 97±2% (n=4), that is, effectively abolished. In contrast, the 

KCl response was reduced by less than half (43±4%, n=5). Our results 

suggest that cold inhibits sour taste transduction at the initial 

transduction channel rather than by blocking downstream Ca2+ influx 

via VGCCs. This observation may be diagnostic of certain proton-gated 

channels. Supported by grant DC00374 (SDR). 


NEURAL ADAPTATION TO ACID STIMULI IS MODULATED 

BY THE BASOLATERAL NA+-H+ EXCHANGER-1 (NHE-1) IN 

FUNGIFORM TASTE RECEPTOR CELLS (TRCS) 

Desimone J.A. 1, Lyall V. 1, Phan T.T. 1, Vinnikova A.K. 2, Heck G.L. 1 

1Physiology, Virginia Commonwealth University, Richmond, VA; 

2Internal Medicine, Virginia Commonwealth University, Richmond, VA 

The role of NHE-1 in neural adaptation to acidic stimuli was 

investigated by intracellular pH (pH ) measurements in polarized rat 

i 

fungiform TRCs and chorda tympani (CT) nerve recordings. In 

- + CO /HCO -free media (pH 7.4), basolateral Na removal decreased 

2 3 

TRC pH and zoniporide, a specific NHE-1 blocker, inhibited the Na i + - 

induced decrease in pH . The TRC pH recovery rate from NH Cl pulses 

i i 4 

was inhibited by basolateral zoniporide with a K of 0.33 µM. 

i 

Basolateral ionomycin reversibly increased TRC Ca2+ , resting pH , and i 

the pH recovery rate from an NH Cl pulse. These effects of Ca i 4 2+ were 

blocked by zoniporide. The lingual application of zoniporide increased 

the magnitude of the CT responses to acetic acid and CO , but not to 

2 

HCl. Lingual application of ionomycin did not affect the phasic part of 

the CT responses to acidic stimuli, but decreased the tonic part by 50% 

of control over a period of about 1 min. This increased adaptation in the 

CT response was inhibited by zoniporide. Lingual application of 8- 

CPT-cAMP increased CT responses to HCl, but not to CO , and acetic 

2 

acid. In the presence of cAMP, ionomycin increased sensory adaptation 

to HCl, CO , and acetic acid. Thus, cAMP and Ca 2 2+ independently 

modulate CT responses to acidic stimuli. While cAMP enhances TRC 

apical H + entry and CT responses to strong acid, an increase in Ca2+ activates NHE-1, and increases neural adaptation to all acidic stimuli. 

Supported by NIDCD Grants DC-02422 and DC-00122. 

21 


BDNF HAPLOINSUFFICIENT MICE HAVE SELECTIVE 

TASTE LOSS FOR SOUR 

Barrows J. 1, Kinnamon S.C. 2, Vigers A. 1, Finger T.E. 1 1Cell and 

Developmental Biology, University of Colorado Health Sciences 

Center, Denver, CO; 2Colorado State University, Fort Collins, CO 

Taste receptor cells are classified according to morphological and 

histochemical criteria. Type II cells express components of the 

phospholipase C signaling pathway (Clapp et al. 2004), required for 

bitter, sweet, and umami transduction (Zhang et al., 2002). Type III 

cells express brain-derived neurotrophic factor (BDNF) and voltagegated 

calcium channels (Medler et al., 2003). A recent study suggested 

that voltage-gated calcium channels may be required for sour 

transduction (Richter et al., 2003). Taken together, these findings 

suggest that Type III cells may mediate sour transduction. The current 

study tested whether mice haploinsufficient for BDNF have reduced 

sensitivity to sour tastants. The haploinsufficient mice utilized in these 

studies have a portion of the coding region of BDNF replaced by lacZ. 

Taste buds of these BDNF/lacZ mice are smaller than wild type 

littermates (Yee et al., 2003). Mice were tested using 24-hour twobottle 

taste preference for the response to citric acid (1 mM to 30 mM), 

the artifical sweetener, SC45647 (3-100 uM), and the bitter substance, 

denatonium benzoate (0.01 mM to 3 mM). The BDNF/lacZ mice 

appear to be one-half log unit less sensitive to citric acid compared to 

wild type animals but do not differ from wild types in sensitivity to 

denatonium or SC45647. These data suggest that sour taste may be 

specifically impacted in BDNF haploinsufficient mice and suggest that 

BDNF-expressing Type III taste cells are necessary for sour taste 

transduction. Funded by NIH Grants DC006070, DC00244 and P30 

DC04657. 

84 Poster [ ] Gustatory Processing 

THE AMILORIDE-SENSITIVE NA-CHANNEL AND NACL- 

QUININE MIXTURE INHIBITION IN THE CHORDA 

TYMPANI 

Formaker B.K. 1, Dowling R.S. 1, Frank M.E. 2 1Oral Diagnosis, 

University of Connecticut, Farmington, CT; 2BioStructure & Function, 

University of Connecticut, Farmington, CT 

NaCl inhibits chorda tympani (CT) taste responses to quinine·HCl 

(QHCl) when the two compounds are presented together in a mixture 

(Formaker et al., 1996). We tested the hypothesis that activation of the 

amiloride-sensitive Na + channel plays a role in the inhibition of QHCl 

responses by treating the tongue with amiloride and by substituting K + 

for Na + . We recorded taste responses from the CT of 6 golden hamsters 

(Mesocricetus auratus) before and after lingual treatment with 30 µM 

amiloride. Taste stimuli were 30 mM NaCl, 30 mM QHCl, 50 mM KCl 

and the binary combinations of NaCl or KCl with QHCl. Responses to 

500 mM NH 4 Cl were used to normalize response measurements. 

Amiloride treatment effectively eliminated differences between KCl, 

NaCl, and their respective mixtures with QHCl. Without amiloride, 

responses to NaCl-QHCl mixtures equaled responses to NaCl alone. 

With amiloride, the response to the NaCl-QHCl mixture was greater 

than the response to either mixture component and less than the 

response predicted by additivity, F(3,15) = 46.1, p


CHEMICAL AND THERMAL RESPONSES OF GUSTATORY 

NEURONS IN THE GENICULATE GANGLION 

Breza J.M. 1, Curtis K. 1, Contreras R.J. 1 1Department of Psychology and 

Program in Neuroscience, Florida State University, Tallahassee, FL 

We examined chemical and thermal responses of gustatory neurons 

(N=18) in the geniculate ganglion using extracellular single-cell 

electrophysiology. Cells were categorized by responses to lingual 

stimulation with the 4 classic tastants: NaCl (100mM), QHCl (20mM), 

sucrose (500mM), and citric acid (10mM) at a baseline temperature of 

25°C. Responses to temperature change of 1°C/s/15s (±15°C) also 

were measured. Finally, responses to the 4 tastants were evaluated after 

adaptation to 40°C and to 10°C. We recorded from 1 Na-specialist 

(5.6%), 1 QHCl-best (5.6%), 2 acid-best (11.1%) and 14 Na-generalists 

(77.8%). Temperature change affected firing in only 3/18 cells (16.7%) 

and only when cooled from 40° to 25°C. Specifically, 2 Na-generalists 

increased firing by 1.1spikes/s (sps) during cooling and the QHCl-best 

cell increased by 2.9sps. After 3-5min adaptation to 10°C, responses to 

all chemical stimuli decreased in all cells, with the responses to the best 

stimulus reduced by 2.5±0.3sps. The most robust decrease in activity 

occurred in the QHCl-best cell (-4.9sps); acid best cells decreased firing 

by -3.9sps. In contrast, after 3-5min adaptation to 40°C, responses 

increased to the best stimulus in 10/16 cells tested (62.5%): 2/2 acidbest 

(+1.9sps) and 8/13 Na-generalists (+2.0±0.4sps). Responses 

decreased or were not affected in the remaining 6 cells: 5/13 Nageneralists 

(-0.8±0.5sps) and the QHCl-best cell (-1.5sps). Thus, 

temperature differentially affects responses of geniculate ganglion 

neurons to taste stimuli. Supported by NIH Grant DC 04875. 


FEEDING RELATED PEPTIDES: INVOLVEMENT WITH THE 

GUSTATORY SYSTEM IN THE BRAIN OF GOLDFISH 

(CARASSIUS AURATUS) 

Huesa G. 1, Finger T. 2 1University of Colorado Health Sciences Center, 

Denver, CO; 2Cell and Developmental Biology, University of Colorado 

Health Sciences Center, Denver, CO 

Melanin Concentrating Hormone (MCH) and Hypocretins (Hcrt) - 

also called orexins-, are peptidergic neurotransmitters expressed 

primarily in neurons located in the lateral hypothalamus. This region is 

known to have a critical role in control of feeding and these peptides 

actively participate in the modulation (stimulation) of food intake. To 

test whether these orexigenic peptidergic systems are involved in the 

gustatory information processing we examined their distribution in 

gustatory nuclei of the CNS of goldfish. For this purpose we employed 

immunocytochemical techniques using polyclonal antisera directed 

against MCH or Hcrt2. The reaction was developed with 

diaminobenzidine to enhance the intensity of the labeling. The 

distribution of these two peptides was similar to those described in 

mammals, with cell bodies in the hypothalamic region and fibers 

projecting rostrally and caudally. Hcrt2 immunoreactive fibers are 

located mainly in preoptic areas, hypothalamus, a few mesencephalic 

regions and the dorsal horn in the spinal cord, but are scarce in taste 

related brainstem nuclei. In contrast, MCH fibers were present in many 

encephalic regions including the vagal gustatory lobe. These MCH 

fibers occur mainly in layer IV of the sensory zone of the vagal lobe, 

where many primary gustatory afferents terminate. In addition, 

occasional MCH fibers could be observed crossing the sensory zone, in 

layer IX and also in fiber and motor layers. These results support the 

concept that MCH but not Hypocretins may act as a central modulator 

of gustatory processing in goldfish. Supported by NIDCD Grant: 

DC00147 

22 


EXPRESSION OF NEUROTRANSMITTER RECEPTORS 

WITHIN THE NUCLEUS OF THE SOLITARY TRACT OF THE 

HAMSTER 

Ye M.K. 1, Rubrum A.M. 1, Christy R.C. 1, Smith D.V. 1 1Anatomy & 

Neurobiology, University of Tennessee Health Science Center, 

Memphis, TN 

The nucleus of the solitary tract (NST) processes taste information 

from the periphery that is modulated by descending projections from 

several areas of the forebrain. Glutamate receptors (GluR) mediate 

peripheral excitation of all taste-responsive NST neurons: Both 

AMPA/kainate and NMDA antagonists block driven activity. Subsets 

of these neurons are excited by microinjection of substance P and 

inhibited by local infusion of γ-aminobutyric acid (GABA) or metenkephalin. 

To further delineate the neural circuitry involved in these 

modulatory effects, we are examining the expression of a number of 

neurotransmitter receptors in the NST. Serial coronal or horizontal 50- 

µm sections through the hamster brainstem were processed for 

immunoreactivity to antibodies directed against µ- and δ-opioid 

receptors, glutamate receptor subtypes GluR-1, -3 and -4 (AMPA) and 

GluR-6 (kainate), the tachykinin receptor NK1, and the GABAA receptor. A given brain was processed using the ABC method for one 

of these eight antibodies. Cells within the gustatory region of the NST 

expressed GluR-1, -3, -4 or –6, the NK1, or the GABA receptor. 

A 

Afferent fibers of the VIIth and IXth nerves entering the solitary tract 

expressed the µ-opioid receptor, whereas the δ-opioid receptor was seen 

in cells of the NST, including the gustatory zone. This pattern of 

expression would suggest a substrate for both pre- and postsynaptic 

inhibition of gustatory neurons. Further work will examine receptor 

expression in physiologically characterized NST neurons. Supported 

by NIDCD DC000066 to DVS. 


PAIRED PULSE FACILITATION AND DEPRESSION 

OBSERVED IN TASTE CELLS IN THE RAT NUCLEUS OF 

THE SOLITARY TRACT FOLLOWING 

GLOSSOPHARYNGEAL NERVE STIMULATION 

Hallock R. 1, Di Lorenzo P. 1 1Psychology, State University of New York 

at Binghamton, Binghamton, NY 

Evoked responses from paired pulse stimulation of the 

glossopharyngeal (GP) nerve was studied in taste responsive cells in the 

nucleus of the solitary tract (NTS) of anesthetized rats. Adult male rats 

were anesthetized with urethane (1.4 g/kg) and Nembutal (25 mg/kg) 

and prepared for unilateral electrical stimulation of the lingual branch 

of the GP nerve and for electrophysiological recording from the 

ipsilateral NTS. Once a taste-responsive cell was isolated, responses to 

taste stimuli (0.1 M NaCl, 0.5 M sucrose, 0.01 M quinine HCl, 0.01 M 

HCl) and electrical stimulation of the GP nerve were recorded. Up to 

100 Pairs of pulses were delivered to the GP nerve at various interpulse 

intervals and responses from cells were recorded. For each cell, the 

threshold for stimulation of the nerve that evoked a response was 

determined and a slightly higher current level was used for subsequent 

stimulation. Electrical pulses were .2 ms in duration and the maximum 

current level was 1.5 mA. Thus far, both paired pulse facilitation and 

depression have been demonstrated in taste cells in the NTS in response 

to stimulation of the GP. Much like paired pulse depression that has 

been previously demonstrated with stimulation of the chorda tympani 

nerve, paired pulse facilitation and depression in the GP may be 

mechanisms by which cells integrate incoming information, modify the 

responses of other cells, or enable the system to increase contrast 

among taste stimuli. 

Supported by NIDCD grant 1-RO1-DC005219 to PMD.


SINGLE TASTE-RESPONSIVE NEURONS IN THE NUCLEUS 

OF SOLITARY TRACT PROJECT AXONS TO BOTH 

PARABRACHIAL AND HYPOGLOSSAL NUCLEI: AN IN- 

VIVO INTRACELLULAR RECORDING AND LABELING 

STUDY 

Li C.X. 1, Li C.S. 1, Smith D.V. 1, Waters R.S. 1 1Anatomy and 


Memphis, TN 

We examined the axonal projections of individual taste-responsive 

neurons of the nucleus of the solitary tract (NST) of hamsters using 

intracellular recording and labeling. The activity of NST neurons was 

recorded intracellularly to determine their intrinsic firing patterns and 

their responses to lingual stimulation with anodal current and with 

sucrose, NaCl, citric acid, and quinine. Recorded cells were labeled 

with 2% biocytin (500 ms, 1 na, 1.4 Hz, 6–40 min); a minimum of 2.5 

hrs was imposed between cell labeling and perfusion to permit axonal 

transport. Hamsters were given lethal injections of Nembutal and 

perfused with chilled 4% paraformaldehyde. Brains were removed, 

refrigerated in fixative overnight, and sectioned at 100 µm in a 

horizontal or sagittal plane. Sections were incubated in ABC and 

reacted with DAB to reveal the labeled cell and counterstained with 

cytochrome oxidase to visualize brainstem nuclei and tracts. To date, 

we have injected six cells (3 multipolar, 2 elongate, 1 bipolar-like) and 

traced the axonal projections to medial and lateral divisions of the 

parabrachial nuclei (PbN) for three cells. In two cells, NST axons 

projected to both the PbN and the hypoglossal nucleus. NST axons 

contained bouton-like swellings along their axonal pathway as well as 

in their terminal fields. These results suggest that a single class of NST 

cells can provide output to three or more separate synaptic targets. 

Supported by NSF IBN-9724092 to RSW and NIH DC000066 to 

DVS. 


TASTE-EVOKED RESPONSES IN THE NUCLEUS OF THE 

SOLITARY TRACT OF C57BL/6BYJ AND 129P3/J MICE. 

Mccaughey S. 1, Bachmanov A. 1 1Monell Chemical Senses Center, 


Although mice offer several advantages for examining the role of 

genetic factors in taste sensation, gustatory responses have been 

recorded only from the periphery in this species. In the present 

experiment, the properties of cells in the first central gustatory relay, the 

nucleus of the solitary tract (NST), were determined in male 

C57BL/6ByJ (B6) and 129P3/J (129) mice. Animals were anesthetized, 

a surgery was performed to expose the surface of the brainstem, and 

neural activity was measured using glass micropipettes. When the 

activity of a single neuron was isolated, a stimulus array that included 

100 mM NaCl, 500 mM sucrose, 10 mM HCl, and 20 mM quinine HCl 

was applied to the tongue and oral cavity. Taste-responsive units were 

found at coordinates relative to obex that correspond to the location of 

the rostral NST in mouse neuroanatomical atlases. We recorded the 

activity of 18 single cells in B6 mice and 13 cells in 129 mice. 

Responses to sucrose were significantly larger in B6 mice. In both 

strains, the properties of cells were similar to those reported previously 

for rats, including breadth-of-tuning values that averaged 0.8. This 

represents a large increase over breadth-of-tuning values reported 

previously for peripheral gustatory neurons in mice, and it suggests that 

peripheral fibers with different response profiles converge onto the 

same NST neurons in these animals. The larger neural response to 

sucrose in B6 mice may underlie their higher preference for this 

compound in long-term tests. This work was supported by NIH grant 

R03 DC005929. 

23 


THE EFFECT OF FLOW RATE ON THE TEMPORAL 

STRUCTURE OF A TASTE RESPONSE RECORDED FROM 

THE NUCLEUS OF THE SOLITARY TRACT IN THE RAT 

Rugai N. 1, Hallock R.M. 1, Di Lorenzo P.M. 1 1Psychology, State 

University of New York at Binghamton, Binghamton, NY 

Recent work has suggested that taste quality may be encoded by the 

temporal structure of initial 2 sec of response (Di Lorenzo & Victor, 

2003) in the nucleus of the solitary tract (NTS). Data from Smith and 

Bealer (1975) in the whole chorda tympani nerve (CT) in the hamster 

suggest that this interval may also contain information about stimulus 

flow rate. Here, the effects of flow rate on the temporal structure of 

taste responses in the NTS of anesthetized rats were examined. Taste 

responses to high (5 ml/s) and low (3.0 ml/s) flow rates of NaCl (0.1 M) 

were recorded from taste responsive cells in the rostral nucleus of the 

solitary tract (NTS). Each trial consisted of 10 s spontaneous activity, 

10 s distilled water, 5 s NaCl, 5 s post-stimulus pause, and a 20 s water 

rinse. The inter-stimulus interval was a 2 min. Low and high flow rates 

were alternated, and multiple replications were presented. Results 

indicated that approximately half of the taste cells also showed 

evidence of tactile responsiveness. Approximately half of the cells 

showed identical response to NaCl presented at high and low flow rates. 

A minority of cells showed an enhanced phasic response related to the 

high flow rate, similar to results in the hamster CT. Another subset of 

cells showed the opposite effect. Results indicate that flow rate is 

encoded within taste responses of NTS cells and that some cells may be 

more sensitive to flow rate than others. 

Supported by NIDCD grant 1-RO1-DC005219 to PMD 


GUSTO-SALIVARY REFLEX CIRCUITS IN RAT BRAINSTEM 

Fukami H. 1, Bradley R.M. 1 1Biologic & Materials Sciences, University 

of Michigan, Ann Arbor, MI 

Neural circuits underlying taste-salivary reflexes have been studied 

in rat brainstem slices. Parasympathetic neurons innervating the lingual 

(von Ebner) and parotid salivary glands were retrogradely labeled by 

application of fluorescent Alexofluor dextran to either the 

glossopharyngeal or otic ganglion and whole cell patch clamp 

recordings made from the labeled neurons. Neurons were first 

visualized with fluorescent illumination and once a neuron was selected 

for recording, it was imaged using differential interference contrast 

infrared microscopy. The electrode also contained Lucifer Yellow (LY) 

to fill the recorded neuron for subsequent identification. After 

recording, the LY filled neurons were imaged using a confocal 

microscope, reconstructed and morphometrically analyzed. Successful 

recordings have been made from 86 neurons. Based on morphometric 

measurements neurons innervating the parotid gland are significantly 

larger than those innervating the lingual glands. Using various current 

injection protocols two major groups of neurons have been defined 

based on biophysical and repetitive discharge characteristics. The 

majority of the neurons have an action potential discharge pattern that is 

modified by the interaction of excitatory and inhibitory synaptic input, 

while the minority of neurons transmit the afferent input pattern 

unchanged. Since all post-synaptic potentials recorded from the 

parasympathetic neurons were a complex mixtures of excitatory and 

inhibitory potentials considerable processing of afferent taste input 

occurs to determine the output pattern of discharges transmitted by the 

secretomotor neurons. 

Supported by NIH grant DC000288 to RMB.


ALCOHOL ACTIVATES A SUCROSE-RESPONSIVE 

GUSTATORY NEURAL PATHWAY 

Lemon C.H. 1, Brasser S.M. 1, Smith D.V. 1 1Dept. of Anatomy & 


Memphis, TN 

A strong association exists between the intake of alcohol and sweettasting 

substances. The neural mechanisms underlying this relationship 

are unknown, although recent data suggest that gustatory factors are 

involved. Here, we explored the role of taste receptors and CNS circuits 

for sugar taste in the gustatory processing of ethanol. Taste responses to 

ethanol (3, 5, 10, 15, 25 and 40% v/v) and stimuli of different taste 

qualities (e.g., sucrose, NaCl, HCl and quinine-HCl) were recorded 

from neurons of the nucleus of the solitary tract in anesthetized rats 

prior to and following oral application of the sweet receptor blocker 

gurmarin. The magnitude of ethanol-evoked activity was compared 

between sucrose-responsive (S , n = 21) and -unresponsive (S , n = 20) 

1 0 

neurons and the central neural representation of ethanol taste was 

explored using multivariate analysis. Ethanol produced robust 

concentration-dependent responses in S neurons that were dramatically 

1 

larger than those in S cells (P's ≤ 0.02). Gurmarin treatment selectively 

0 

and similarly inhibited ethanol and sucrose responses (P's ≤ 0.01). 

Across-neuron patterns of response to ethanol were most similar to 

those evoked by sucrose (multiple r = +0.89), becoming increasingly 

more so as the ethanol concentration was raised. Results implicate taste 

receptors for sucrose as candidate receptors for ethanol and reveal that 

alcohol and sugar taste are represented similarly by activity in the CNS. 

These findings have important implications for the sensory and hedonic 

properties of alcohol. Supported by NIH DC005270 and DC00353. 


CHARACTERIZATION OF RAT ORBITOFRONTAL 

CORTICAL NEURONS DURING AD LIBITUM DRINKING OF 

LIQUID REWARDS. 

Gutierrez R. 1, Nicolelis M.A. 1, Simon S.A. 2 1Neurobiology, Duke 

University, Durham, NC; 2Anesthesiology, Duke University, Durham, 

NC 

In gustatory physiology, the orbitofrontal cortex (OFC) contains 

neurons that have roles in tongue movements, satiety, and other 

motivational outcomes involved in obtaining rewards. There is, 

however, a paucity of information regarding the nature of the OFC 

responses obtained from freely-moving rats licking to obtain a reward. 

To this end we have chronically implanted bundles of electrodes in rat 

OFC while they were free to drink from a sipper tube water or a sucrose 

solution. 172 single unit responses were characterized. A crosscorrelogram 

analysis between licking and neural activity revealed that 

17% of the responses faithfully followed the licking frequency (~ 7 

Hz). Of these oscillating neuronal responses, 24% responded either 

more actively or with a different morphology when drinking sucrose 

than water, probably reflecting the differential reward values of these 

stimuli. To obtain a better understanding of the neuronal activity 

involved in the initiation of a licking bout, peri-event histograms were 

constructed using the onset of the first lick after at least a 1 sec pause. 

Four other morphologically distinct types of responses were identified. 

Relative to the initiation of a drinking bout: two types began firing 

before (anticipatory), one type decreased firing and the other increased 

firing. In summary, five types of OFC neurons have been identified. 

Two, as expected, are related to the anticipation of a reward; others 

however are related to licking, and to the nature of the reward. 

Supported by NIH DC-01065. 

24 

95 Poster [ ] Olfactory CNS Physiology and Coding 

ONTOGENY OF SENSORY-EVOKED RESPONSES IN RAT 

AMYGDALA 

Wilson D.A. 1 1Department of Zoology, University of Oklahoma, 

Norman, OK 

The amygdala plays a critical role in emotion and memory. Recent 

work has suggested that adult reactions to emotional and/or stressful 

stimuli can be shaped by the effects of early experience on amygdala 

functional ontogeny. However, while ontogeny of amygdala neuron 

phenotype and neuroananatomy have been described, very few 

descriptions of amygdala physiology and function during the postnatal 

and adolescent period exist. As a first step toward understanding how 

early experiences shape amygdala function, the present study examined 

amygdala single-unit activity and responsiveness to sensory input 

during postnatal development. 

Single-unit and local field potential (LFP) activity were recorded in 

amygdala nuclei (primarily basolateral) of urethane-anesthetized, Long- 

Evans hooded rats. Rats were aged PN10 to adult (> PN70). 

Spontaneous activity, odor-evoked and footshock-evoked activity were 

determined for each cell using peri-stimulus time histograms. 

Spontaneous activity increased and evoked response latency decreased 

with age. While both odor-evoked and footshock-evoked responses 

could be observed at all ages, the temporal structure of these responses 

changed dramatically over the age range tested. Odor-evoked LFP's 

showed strong oscillations in the high beta band in adults, however the 

primary frequency of these oscillations shifted to lower ranges in 

younger animals toward the theta range at PN10. Given the 

hypothesized importance of temporal structure in stimulus encoding, 

these developmental changes may be indicative of a slow postnatal 

emergence of mature sensory processing by the rat amygdala, perhaps 

contributing to the sensitivity of this structure to early experiences. 


FACILITATION OF MAIN OLFACTORY INPUT TO THE 

MEDIAL AMYGDALA AND MEDIAL PREOPTIC AREA BY 

GONADOTROPIN-RELEASING HORMONE (GNRH). 

Blake C. 1, Westberry J. 1, Case G.R. 1, Meredith M. 1 1Neuroscience, 


Sensory signals received during mating activate brain regions along 

the vomeronasal pathway and the medial preoptic area. These activated 

regions contain cell bodies and fibers of gonadotropin-releasing 

hormone (GnRH) neurons, suggesting a possible relationship between 

chemosensory input and GnRH. Chemosensory input can be detected 

by the vomeronasal organ and/or the main olfactory system. The 

consequences of vomeronasal organ removal (VNX) are most apparent 

in sexually naïve animals. Experienced, but not inexperienced, male 

hamsters can use main olfactory input to maintain mating after VNX, 

suggesting that with experience, neural circuits acquire the ability to use 

main olfactory information as the essential chemosensory input for 

mating. GnRH has also been shown to restore mating behavior in naïve 

VNX male hamsters. GnRH may facilitate transfer of olfactory 

information to the medial amygdala and medial preoptic area (MPOA) 

in naïve intact and VNX males. Electrical stimulation of the main 

olfactory bulb activates neurons in anterior and posterior medial 

amygdala and increases expression of FRAs (Fos-related antigens) 

protein. Initial experiments indicate an icv injection of GnRH into the 

lateral ventricle increases activation in medial amygdala and medial 

preoptic area. These experiments examine the effect of GnRH on 

chemosensory information transfer via the main olfactory pathway to 

these regions that are involved in mating behavior driven by either 

chemosensory pathway. Supported by DC-005813 from NIDCD.


ODOR RESPONSES OF CEREBRAL LOBE NEURONS 

Nikonov A.A. 1, Caprio J. 1 1Biological Sciences, Louisiana State 

University, Baton Rouge, LA 

Functional information as to how odors are processed at more central 

neural levels than the olfactory bulb (OB) is fragmentary at best in 

mammals and nonexistent in teleosts. The long-term goal is to 

determine similarities and differences in how odor information arriving 

via the olfactory tracts is processed within the cerebral lobes (CL) of 

the channel catfish compared to that in the OB. Odor-responsive 

neurons were located in caudo-medial and lateral regions of the CL as 

predicted from previous forebrain anatomical investigations (Finger, 

1975; Bass, 1981). Recordings were performed in vivo with metal-filled 

glass microelectrodes. Tested were bile salts (taurocholic and 

taurolithocholic acids) and amino acids (L-methionine and L-arginine), 

effective odor stimuli in channel catfish (Nikonov & Caprio, 2001). 

Sixty-four CL neurons responded to the odor stimulation; 45 were 

excited and 19 were suppressed (12 by amino acids and 7 by bile salts). 

Fifteen units located medially in the CL were excited by bile salts and 

were unresponsive to amino acids. Twenty-six of the 30 excitatory units 

located more laterally responded to 0.1-100µM amino acid; 4 additional 

units within this region along the OB midline responded to bile salts. 

The medial-lateral distinction between excitatory responses to bile salts 

and amino acids reflects a similar topographical organization within the 

OB. Ongoing experiments will determine if an odotopic map as 

observed in the OB (Nikonov and Caprio, 2001) exists or is altered 

within the CL and whether the response properties of CL neurons are 

different from those of OB neurons to the same odors. 

Supported by NSF IBN-0314970 and NIH DC-03792 


ODOR REPONSIVENESS OF THE OLFACTORY CORTEX 

AND RESIDUAL TYROSINE HYDROXYLASE ACTIVITY IN 

THE OLFACTORY BULB IN THE CNGA2 KNOCKOUT 

MOUSE 

Lin W. 1, Restrepo D. 1 1Cell and Developmental Biology, Neuroscience 

Program and Rocky Mountain Taste and Smell Center, University of 

Colorado Health Sciences Center, Denver, CO 

Mice deficient for subunit A2 of the cyclic nucleotide-gated (CNG) 

channel respond to select odorants (see Restrepo et al abstract in this 

meeting of AChemS). We examined the presence of alternate 

transduction pathways and the potential role of necklace glomeruli, 

which receive axons from neurons expressing the cGMP pathway 

(Juilfs et al 1997, PNAS 94:3388-95) and remain active in CNGA2 KO 

mice (Baker et al 1999, J Neurosci. 19:9313-21). Immunoreactivity to 

the cGMP-stimulated phosphodiesterase (PDE2), tyrosine hydroxylase 

(TH) and odor-induced Fos was used to visualize necklace glomeruli, 

levels of glomerular activity and activation respectively. We found that 

the TH expression in juxtaglomerular cells surrounding PDE2-positive 

necklace glomeruli is dependent on afferent input as unilateral naris 

occlusion dramatically reduced the TH expression in CNGA2 KO mice. 

Importantly, exposure CNGA2 KO mice to a mixture of putative 

pheromones (2-heptanone and 2, 5-dimethylpyrazine) increased odorevoked 

Fos induction in juxtaglomerular cells of some necklace and 

regular glomeruli. Further, we observed Fos expression in a 

substantially larger number of cells in both the anterior olfactory 

nucleus (AON) and piriform cortex in CNGA2 knockout mice 

compared to the same regions from mice exposed to fresh air. These 

experiments provide evidence for alternate transduction pathways in the 

main olfactory system in mice. 

This work was supported by NIH grants DC00566, DC04657, 

DC006070 (DR) and DC0043(WL). 

25 


SYNAPTIC MECHANISMS CONTRIBUTING TO OLFACTORY 

CORTICAL ADAPTATION 

Best A.R. 1, Wilson D.A. 1 1Zoology, University of Oklahoma, Norman, 

OK 

Anterior piriform cortex (aPCX) neurons rapidly filter repetitive odor 

stimuli despite relatively maintained input from mitral cells. This 

cortical adaptation is correlated with short-term depression of afferent 

synapses, in vivo. The purpose of this study was to elucidate 

mechanisms underlying this non-associative plasticity using in vivo and 

in vitro preparations and to determine its role in cortical odor 

adaptation. We have previously described our in vitro stimulation 

results. In particular, we have discovered that the longer lasting portion 

(~120 s) of the in vitro short-term synaptic depression can be blocked 

pharmacologically. Following 50 s of simulated odor stimulation, either 

the metabotropic glutamate II/III antagonist CPPG (500 µM) or the βadrenergic 

receptor agonist isoproterenol (20 µM) can decrease the 

duration of synaptic depression. More recently we have discovered that, 

in vivo, both adaptation of odor responses in the β (15-35 Hz) spectral 

range and the associated synaptic depression following a 50 s exposure 

to a mixture of odorants can also be blocked by intracortical infusion of 

CPPG (2.5 mM). Currently, we are extending this work to behavioral 

habituation using heart rate orienting response habituation as a measure 

of cortical adaptation. Prior to adaptation of the heart rate orienting 

response, 3 µl of 2.5 mM CPPG or vehicle will be infused into aPCX 

bilaterally. Results from the behavioral paradigm will assist in 

clarifying the independent roles of receptor adaptation and cortical 

adaptation in behavioral habituation to odors. Funded by NICHD. 

100 Slide [ ] Olfactory CNS Physiology and Coding 

RAPID ODOR CHANGE AND BRAIN ELECTRICAL 

ACTIVITY 

Lorig T.S. 1, Rigdon M. 1, Poor A. 1 1Washington and Lee University, 

Lexington, VA 

Some odors produce increased activity in areas of the brain often 

associated with language even though the task demands do not 

explicitly involve language. Visual and auditory stimuli which change 

rapidly tend to produce more left temporal lobe activity than stimuli 

that change slowly. If odor mixtures are transduced in such a way that 

each component produces high temporal overlap with the other 

components, this should effectively be construed as rapid stimulus 

change and lead to more left temporal lobe responses. To test this 

hypothesis, 10 undergraduate students served as subjects in a 

chemosensory event-related potential (CSERP) study. Three odors, 

phenethyl alcohol, vanillin, and citral were presented in binary pairs via 

a constant flow olfactometer and stimulus administration was triggered 

by subjects' inhalation. The stimuli were presented in two different 

ways. Given the members of the binary odor pair, A and B, one 

condition (Slow) required subjects to smell a sequence of A followed 

by B. Both A and B lasted 300 msec and were counterbalanced. In the 

Fast condition, the sequence was A,B,A,B where each stimulus lasted 

150 msec and was counterbalanced. In both cases, each odor lasted a 

total of 300msec and the total stimulus administration lasted 600msec. 

CSERP data were collected from 80 scalp locations. Analysis revealed 

that brain activity differed between the two types of stimulus 

administration. Subsequent analysis with LORETA indicated that the 

left temporal lobe was more active in the Fast condition supporting the 

hypothesis that temporal overlap in odor mixtures leads to more left 

temporal lobe activity.


PET ACTIVATIONS DURING SMELLING OF 

ANDROSTENONE: OSMICS VERSUS ANOSMICS 

Boyle J.A. 1, Zatorre R. 1, Pause B. 2, Jones Gotman M. 1 1McGill 

University, Montreal, Quebec, Canada; 2Christian-Albrechts- 

University, Kiel, Germany 

We used positron emission tomography to evaluate the neural 

correlates involved in perception of the endogenous steroid 

androstenone. Our aim was to investigate whether differences exist in 

brain activations between subjects with high sensitivity (low thresholds) 

for androstenone and those with a specific anosmia. We screened 87 

subjects using a staircase procedure to establish individual thresholds. 

Twelve subjects unable to detect the steroid in its crystal form were 

selected for an anosmic group, and 12 subjects capable of consistently 

detecting a 1.4 x 10-7 M solution of androstenone comprised an osmic 

group. Subjects were scanned during passive smelling of phenyl ethyl 

alcohol (PEA), pyridine, androstenone (AND) or the diluant (for 

baseline). Our first analysis compared brain responses of the two groups 

to two of these stimuli: PEA and AND versus baseline. Activations for 

PEA were observed in olfactory regions, including orbitofrontal and 

piriform cortex, in both subject groups. However, osmics and anosmics 

differed in their response to AND. Osmics showed more activity in the 

dorsomedial area of the left parietal cortex and had no significant 

olfactory activations, whereas anosmics showed more frontal 

activations in the right dorsomedial and orbitofrontal regions. The 

results for PEA are consistent with other studies of olfactory 

processing, showing activations in olfactory cortices, whereas the AND 

results suggest differential function in the human brain related to 

individual sensitivity to androstenone. Implications of the parietal lobe 

activations will be discussed. Supported by Canadian Institutes of 

Health Research 


FUNCTIONAL NEUROIMAGING OF ODOR IMAGERY 

Djordjevic J. 1, Zatorre R. 1, Petrides M. 1, Boyle J. 1, Jones Gotman M. 1 

1Montreal Neurological Institute, Montreal, Quebec, Canada 

We used positron emission tomography to investigate brain regions 

associated with odor imagery. We compared changes in brain activation 

during active imagination of odors versus those during nonspecific 

expectation of olfactory stimuli, and during experience of physically 

presented versus imagined odors. Sixty-seven healthy volunteers were 

screened for their odor imagery (with a paradigm developed in a 

previous study), and 12 of them, selected as “good odor imagers”, 

participated in the neuroimaging study. Comparison of odor imagery 

with general expectation of odors revealed activation in the left primary 

olfactory cortex (POC) including piriform cortex, as well as in the 

insula bilaterally, and the left posterior orbitofrontal cortex (OFC). On 

the other hand, comparison of odor perception with an odorless baseline 

resulted in increased activation bilaterally in the piriform and insular 

cortex and in the right posterior OFC. Results of a conjunction analysis 

revealing regions of common activation during odor perception and 

imagery were convergent with the results obtained by the subtraction 

method: left piriform cortex and bilateral insula were activated both 

when smells were perceived and imagined. Findings also suggested a 

differential role of the right versus left posterior OFC in perceptual 

versus imaginal olfactory processing: whereas the right OFC was 

activated during odor perception, the same region of the left hemisphere 

was activated during odor imagery. Overall, the findings indicated that 

neural networks engaged during odor perception and imagery partially 

overlap. 

Supported by Canadian Institutes of Health Research 

26 

103 Slide [ ] Olfactory CNS Physiology and Coding 

NEURAL SUBSTRATES UNDERLYING MENTAL IMAGERY 

OF PLEASANT AND UNPLEASANT SMELLS 

Bensafi M. 1, Porter J.A. 2, Khan R.M. 1, Mainland J. 1, Johnson B. 3, 

Zelano C. 4, Sobel N. 1 1Neuroscience, University of California, 

Berkeley, Berkeley, CA; 2Psychology, University of California, 

Berkeley, Berkeley, CA; 3Bioengineering, University of California, 

Berkeley, Berkeley, CA; 4Biophysics, UC Berkeley, Berkeley, CA 

Patterns of neural activity in orbito-frontal cortex (OFC) reflect odor 

valence: the medial OFC responds preferentially to pleasant odors, 

whereas the lateral OFC responds preferentially to unpleasant odors. 

Whether this dissociation exists during odor imagery in the absence of 

any odorants is unknown. Here, we approached this question using 

fMRI (4T). Sixteen subjects (8f) were tested in an event-related design 

with 5 trial types, each repeated 22 times (TR=500ms, ISI=30sec). In 3 

sensory trial types, a pleasant odor (strawberry), an unpleasant odor 

(rotten eggs) and a non-odorized control were presented by air dilution 

olfactometer. In 2 imagery trial types, no odorants were presented, but 

subjects were asked to imagine the same smells (strawberry, rotten 

eggs). Replicating previous reports, initial analysis revealed a 

dissociation during perception whereby strawberry induced a significant 

activation in medial OFC, whereas rotten eggs induced an increase in 

lateral OFC (p

105 Poster [ ] Unicellular Chemoreception 

GPI ANCHORED RECEPTORS IN CHEMOSENSORY 

TRANSDUCTION 

Weeraratne S.D. 1, Valentine M. 1, Yano J. 1, Van Houten J. 1 1Biology, 

University of Vermont, Burlington, VT 

Glycosyl phosphatidylinositol (GPI) anchored proteins are surface 

proteins that are tethered to the cell surface. They serve as receptors of 

ligands in axon guidance and T cell activation among other functions. 

In Paramecium they function in chemoreception. We have shown 

through disruption of anchoring using an antisense expression to PIG-A 

(an enzyme in the fist step in anchor synthesis) that chemoresponses to 

folate and glutamate are almost eliminated. Disruption of the last 

enzyme of anchor synthesis with an RNAi expression vector also 

disrupted chemoresponse, but not as profoundly. The genes for the first 

and last enzymes in the pathway were cloned using homology PCR, and 

with the sequencing of the Paramecium genome, we have identified the 

sequences of the other pathway enzymes. We have examined the 

distribution of the GPI anchored proteins on the cell surface and found 

that they are not evenly distributed across the surface, but rather they 

cluster near the bases of the cilia, where another chemosensory 

transduction component (the plasma membrane calcium pump- PMCA) 

is also found. We show this distribution through confocal and 

deconvolution microscopy using antibodies to the folate chemoreceptor, 

5´ nucleotidase, GPI anchored surface antigens, tubulin and the 

PMCAs. The Paramecium genome project has provided us with 

sequences for putative GPI anchored folate receptors and our 

preliminary results using RNAi-feeding support the hypothesis that at 

least one of these proteins functions in folate chemoresponse. 

Supported by NIH DC00721, GM59988, the Vemont Cancer Center. 


LIPID RAFTS IN CHEMOSENSORY TRANSDUCTION 

Chandran S. 1, Ray K. 1, Yano J. 1, Van Houten J. 1 1Biology, University of 

Vermont, Burlington, VT 

Lipid Rafts are lipid domains high in glycosphingolipids and 

cholesterol that serve as platforms for organizing signal transduction 

components such as GPI anchored proteins, G proteins (large and 

small), serpentine receptors, receptor and non-receptor tyrosine kinases. 

Proteins in lipid rafts are insoluble in cold Triton X-100 and are found 

in low density fractions when the Triton insoluble fractions are 

separated in sucrose or Optiprep gradients. We have found that 

Paramecium surface membranes can be separated in Optiprep gradients 

into fractions by density, and correlated with ganglioside and 

cholesterol levels. Proteins such as the putative folate chemoreceptor 

(and other GPI anchored proteins such as 5´ nucleotidase and surface 

antigens), G-beta, and the plasma membrane calcium pumps separate 

into the light density fractions, supporting the existence of lipid rafts 

that organize these proteins in signaling. When we remove cholesterol 

from the membranes of living cells using methyl-beta-cyclo-dextrin, we 

find that chemoresponse to folate is significantly reduced, implying 

that raft organization is important for chemoresponse. We are also 

using cholera toxin to localize gangliosides as markers of rafts on the 

cell surface, and asking whether removal of cholesterol changes the 

distribution of signaling proteins in Optiprep gradients and on the cell 

surface. Supported by GM59988, DC 00721, and Vermont Cancer 

Center. 

27 


PLASMA MEMBRANE CALCIUM PUMPS FUNCTIONING IN 

CHEMICAL SENSING 

Yano J. 1, Zhukovskaya M. 2, Preston R. 3, Pan Y. 1, Keiser M. 1, Van 

Houten J. 1 1Biology, University of Vermont, Burlington, VT; 

2Pharmacology and Physiology, Drexel University, PA, PA; 

3Pharmacology and Physiology, Drexel University, Philadelphia, PA 

The Plasma Membrane Calcium Pumps (PMCAs) play a role in 

sensory transduction in Paramecium by sustaining the hyperpolarizing 

conductance that is initiated by a K conductance upon stimulus 

application. We identified 4 PMCA isoforms through homology PCR, 

and found that 3 were expressed. The Paramecium genome project 

shows that there are up to 4 more related sequences that probably code 

for additional PMCAs. To explore the roles of these PMCAs we have 

begun to over-express them with and without epitope tags to localize 

them on the cell surface, and found that over expression disrupts 

calcium homeostasis in the cell. The cells´ swimming patterns are 

dependent upon the intraciliary calcium levels, and over-expression of 

the isoforms 2 and 3 cause cells to swim backward for long periods of 

time, consistent with high intraciliary calcium. We have also found that 

the calcium conductance of the voltage gated calcium channels is 

significantly changed in cells over-expressing the isoforms 2 and 3, 

consistent with abnormally high intracellular calcium and defective 

calcium homeostasis. This has allowed us to systematically over 

express the isoforms and ask which chemoresponse is affected. We 

find that isoform 2 over-expression primarily affects folate 

chemoresponse, while isoform 3 over expression affects chemoreponse 

to folate, glutamate, acetate, all of which function through different 

signal transduction pathways, but all of which we believe to include the 

PMCAs. Supported by DC 00721, Vermont Cancer Center. 


THE RYANODINE RECEPTOR ANTAGONIST DANTROLENE 

ALTERS SWIMMING BEHAVIOR AND CAUSES MORTALITY 

IN PARAMECIUM TETRAURELIA 

Green M.H. 1, Brown H.J. 1, Bell W.E. 1 1Biology, Virginia Military 

Institute, Lexington, VA 

Paramecium tetraurelia are unicellular eukaryotes with excitable 

ciliated membranes that use calcium as a regulator of membrane 

potential. Several critical Paramecium functions are known to be 

mediated by calcium such as chemoresponse and exocytosis. Because 

caffeine and 4-chloro-m-cresol stimulation of Paramecium results in an 

increase in intracellular calcium concentration ( Klauke, et al., 2000, J. 

Mem. Biol. 174:141-156), it is possible that a calcium channel similar 

to the ryanodine receptors found in skeletal muscle may be involved in 

calcium mobilization. We examine the effects of the ryanodine 

receptor antagonist, dantrolene, on Paramecium tetraurelia. Dantrolene 

was toxic when applied in doses normally used in mammalian systems 

in the presence of magnesium. It is possible that magnesium, which also 

is a ryanodine receptor inhibitor, amplifies the effect of dantrolene on 

ryanodine-like receptors in Paramecium resulting in toxicity. Also of 

interest is the lack of protection from dantrolene-mediated toxicity in 

the mutant eccentric, which has a defective magnesium conductance. 

Initial experiments indicate that dantrolene does not affect the ability of 

caffeine to increase intracellular calcium levels. Dantrolene does 

however, significantly reduce the backward swimming time of 

Paramecium exposed to depolarizing concentrations of potassium. 

Chemosensory behavior in T-Maze assays to the attractants biotin and 

acetate was not altered by dantrolene treatment in potassium solutions. 

This work was supported by grant J-651 from the Jeffress Memorial 

Trust and a VMI research Grant in Aid.

109 Poster [ ] Clinical Evaluation and Consumer Research 

COMPUTERIZED HISTORY OF OLFACTORY 

DYSFUNCTION 

Cornelia H. 1, Landis B.N. 2, Frasnelli J. 1, Hummel T. 1 1ORL, University 

of Dresden Medical School, Dresden, Germany; 2ORL, University 

Hospital of Geneva, Geneva, Switzerland 

The patient´s/subject´s history is an integral part of investigations on 

human olfactory sensitivity. Numerous ways are being employed to 

obtain information from subjects/patients. Based on Filemaker 

Developer 6.0 (R), the current exercise aimed to produce a relatively 

short, computerized questionnaire which allows subjects/patients to 

enter their data directly into a database in a controlled fashion. Further, 

a separate section is availbale for the examiner to enter data with regard 

to drug intake, qualitative olfactory dysfunction, results of 

chemosensory testing, results from nasal endoscopy, treatment etc. A 

different set of questions is available for return visits. In addition, the 

present approach combines this database with software for the 

computerized testing of olfactory thresholds (triple-forced choice, 

single staircase), odor discrimination (triple forced choice, 16 triplets) 

and odor identification (mutiple forced choice, 16 items). In a clinical 

context, the database allows to create a quick overview across changes 

of olfactory function over time. It is hoped that this approach will 

eventually lead to more complete information from subjects/patients. 

Further, it is hoped that this approach will help to standardise 

information that is obtained at different centers. 


CLINICAL TEST OF OLFACTION BASED UPON A MEMS- 

MICROVALVE OLFACTOMETER. 

Hastings L. 1, Wilson T. 1 1Osmic Enterprises, Inc., Cincinnati, OH 

We describe the development of a clinical test for the assessment of 

olfactory function which incorporates state-of-the-art Micro-Electro- 

Mechanical Systems (MEMS) microvalves. These minature, discrete 

devices form the basis of the MEMS olfactometer, a relatively small, 

inexpensive device capable of producing 40 or more discrete odor 

stimuli. Moreover, the MEMS olfactometer will have the capacity for 

generating the stimuli necessary for a large number of trials (>100). 

This capability can be replenished by replacing inexpensive odor 

cartridges. The initial test selected for development is an odor 

identification test, the paradigm most frequently used to assess 

olfactory function. The test, called the OLFACT (OLfactory Function 

Assessment by Computerized Testing) will be enhanced by inclusion of 

pictures, along with words, in the description of test item choices. The 

presentation of the test items, along with scoring of the test, and 

recording of all pertinent data will be totally computerized. Norms for 

the test will be developed and compared with standardized norms 

already available for other commercial tests. Finally, the test will be 

enhanced to run on the WWW as a Web application. Once a MEMS 

olfactometer has been attached to a computer linked to the WWW, 

administration of the tests can be authorized over the Web. Anonymous 

data can also be collected via the Web for inclusion into a centralized 

database. This test will provide a comprehensive and sensitive system 

for evaluating the sense of smell at a lower cost while providing greater 

utility than current tests. Supported by NIH grant DC 06369 

28 


HEART RATE CHANGES DURING ODORANT 

ADMINISTRATION: PROMOTION OF "COOL-DOWN" AND 

RECOVERY IN COLLEGE ATHLETES 

Smith J. 1, Raudenbush B. 1 1Psychology, Wheeling Jesuit University, 

Wheeling, WV 

An often under-addressed aspect of athletic training, and even casual 

exercise, is the proper amount of time for "cool-down" and recovery. 

However, when an ample recovery period is not available, the 

likelihood of injury and overtraining increases while athletic 

performance decreases. Previous research has shown that odorants can 

affect one's mood, motivation, and task performance. Moreover, 

peppermint odor is linked to enhanced athletic performance, while 

jasmine odor is a proven sleep aid. These unique odorant characteristics 

led to their inclusion within the present experiment in an attempt to 

determine whether jasmine and peppermint odors can enhance athletic 

recovery. In a within-subjects design, twenty athletes performed a 

modified version of the Bruce Stress Test Protocol on a treadmill for 15 

minutes and then completed push-ups until exhaustion. Following 10 

minutes of "cool-down" stretching in a peppermint, jasmine, or no-odor 

condition, physiological data were recorded and the participant 

completed questionnaires related to workload demands and mood. In 

addition, level of vigor was rated over the following twelve hours. 

Jasmine odor significantly reduced athletes' heart rate following the 

"cool-down" period compared to the non-odorized control condition. 

Such a finding supports the hypothesis that odorants may have a 

substantial role in naturally and safely expediting recovery from 

physical exertion. This study was funded by a grant from NASA to B. 

Raudenbush. 


EFFECTS OF PEPPERMINT ODOR ADMINISTRATION ON 

AUGMENTING BASKETBALL PERFORMANCE DURING 

GAME PLAY 

Raudenbush B. 1, Smith J. 1, Graham K. 1, Mc Cune A. 2 1Psychology, 

Wheeling Jesuit University, Wheeling, WV; 2Physical Therapy, 

Wheeling Jesuit University, Wheeling, WV 

Previous research indicates that inhaling peppermint odor prior to 

and during athletic activity increases strength, speed, and endurance. It 

has also been found to reduce fatigue, perceived effort, and perceived 

frustration, and increase levels of vigor and motivation. However, 

assessment of peppermint odor efficacy has yet to be performed during 

actual physical game play. The present study was designed to assess 

whether the degree to which athletes inhale peppermint odor affects 

such aspects as motivation, energy, fatigue, reaction time, confidence, 

and performance during the course of a basketball season. Male and 

female Division II basketball players were provided with a peppermint 

inhaler (Peak PerformanceTM Sports InhalerTM) for use during 

practice and game play. Level of inhalant use constituted group 

composition for data analysis. Higher levels of inhalant use were 

associated with increased motivation, energy, speed, alertness, reaction 

time, confidence, and strength. Levels of fatigue and frustration were 

lower in the high-use group. In addition, athletes' ratings of their 

competitive advantage over opponents and ratings of overall 

performance were enhanced. Implications are particularly salient in 

regards to augmenting a variety of factors related to athletic 

performance using an all-natural, non-pharmacological ergogenic aide.


EFFECTS OF BEVERAGE FLAVOR ON ATHLETIC 

PERFORMANCE, MOOD, AND WORKLOAD 

Schuler A. 1, Rawson A. 1, Raudenbush B. 1 1Psychology, Wheeling Jesuit 

University, Wheeling, WV 

Previous research indicates that the administration of peppermint 

odor can augment athletic performance and mood, and decrease 

workload demands. The present study extended those findings by 

evaluating athletic performance and physiological changes during the 

administration of flavored beverages. Utilizing a within-subjects design, 

athletes performed a 15-min modified treadmill stress test. At 3-min 

intervals, 50 mL of beverage (peppermint water, unadulterated water, or 

Gaterade sports drink) were consumed. In the control condition, no 

beverage was consumed. Pre- and post-testing physiological 

measurements were taken (blood pressure, pulse, oxygen 

concentration). In addition, ratings of mood (via the Profile of Mood 

States) and workload (via the NASA Task Load Index) were completed. 

No physiological changes were noted, however, both the peppermint 

and Gatorade sports drink conditions lead to greater ratings of personal 

performance and increased mood. These results provide additional 

support for the implementation of non-pharmacological methods to 

increase an athlete's performance and mood during exercise and/or 

competition. This study was funded by a grant from NASA to B. 

Raudenbush. 


OLFACTORY LOSS FOLLOWING INTRANASAL ZINC 

GLUCONATE 

Jafek B.W. 1, Linschoten M.R. 2 1Otolaryngology, University of 

Colorado Health Sciences Center, Denver, CO; 2Otolaryngology-Head 

& Neck Surgery, University of Colorado Health Sciences Center, 

Denver, CO 

Beneficial zinc absorption takes place via enteral, parenteral, or 

cutaneous routes. Direct application to the olfactory epithelium, 

however, has been reported to cause loss of smell. Intranasal zinc 

gluconate has recently been recommended as a treatment for the 

common cold. Severe posttreatment hyposmia and anosmia have been 

observed. The case report of a typical patient will be presented and 

analyzed in detail, followed by a series of patients with severe 

hyposmia or anosmia following the use of intranasal zinc gluconate in 

both of the two currently available commercial products. While 

interindividual variation in drug response and drug effect is apparent, 

the loss may be permanent. The mechanism of olfactory loss is thought 

to be the direct effect of the divalent zinc ion on the olfactory receptor 

cell. 

29 


CHEMOSENSORY CHANGES IN ESTROGEN RECEPTOR 

POSITIVE BREAST CARCINOMA: A CASE REPORT 

Bailey M.L. 1, Hirsch A.R. 2 1Lake Erie College of Osteopathic 

Medicine, Erie, PA; 2The Smell & Taste Treatment and Research 

Foundation, Chicago, IL 

ABSTRACT: Despite reduction in appetite in patients with cancer, 

physicians rarely assess chemosensory function. A patient with 

estrogen receptor positive (ER+) breast carcinoma presents with 

chemosensory complaints. 

CASE PRESENTATION: A fifty-five year old female, presented 

with seven months of taste distortion. She initially noted a 

phantageusia of “Windex” which changed to a soapy, metallic 

sensation, localized to the posterior tongue and upper lip. Drinking 

water improved the phantageusia, and consuming sweets, milk, vinegar 

or acidic foods worsened the phantageusia. Taste threshold testing 

revealed hypogeusia to bitter, salt, and sour. Six weeks after 

evaluation, she underwent modified radical mastectomy for ER (+) 

breast carcinoma. Immediately thereafter, the phantageusia resolved 

and her perception of sweet, salty, and sour taste intensified. Repeat 

chemosensory testing one month later on no medications, prior to any 

chemotherapy, demonstrated marked improvement for all taste 

modalities except salt, which remained unchanged. 

DISCUSSION: Possible origins for gustatory deficits include remote 

effects of carcinoma, counter-stimulation from circulating tumorinduced 

hematogenous tastes, tumor released hematogenous synergistic 

tastes, taste bud regeneration inhibition, zinc deficiency, elevated 

calcium or lactate levels, dry mucous membranes, and lack of interest 

and motivation. Chemosensory evaluation is warranted in patients who 

present with ER (+) breast carcinoma. 


ODORANTS AT THE WORLD TRADE CENTER DISASTER 

SITE: ANALYSIS AND PSYCHOLOGICAL IMPACT 

Preti G. 1, Opiekun R. 1, Smeets M. 1, Fatsis S. 2, Dalton P. 1 1Monell 

Chemical Senses Center, Philadelphia, PA; 2The Wall Street Journal, 

Washington, DC 

Odors present during a traumatic event may become associated with 

internal and external aspects of the experience and in turn, can trigger 

an emotional or stress response when encountered at a later time. 

Knowledge of the odor-causing molecules present at disaster sites is 

central to developing a synthetic odor-mimic, which can be used to 

prospectively educate rescue workers and to desensitize those who have 

already developed odor-stress associations. The distinct and pervasive 

odors lingering in the vicinity of lower Manhattan for weeks following 

9-11 were prime candidates for eliciting odor-mediated “flash-backs” 

among worker and residents. To identify and describe the quality of the 

odorants contributing to this unique, but complex, smell, four of the 

authors rated the sensory attributes and collected air samples using 

Tedlar bags and SPME “field units” at two sites surrounding the 

collapsed World Trade Center towers. Using GC-Olfactometry, the 

individuals who experienced the odors at the site evaluated the odorants 

as they emerged from the GC, being particularly careful to identify 

odorants that could be linked to the characteristic odor of the site. Many 

of the characteristic odorants were linked to specific compounds (eg 

“smokey” from guiacol; “sour/musty” from C7 to C9 acids; ) or small 

groups of compounds (“musty/burnt” and irritating/vinegar-like from a 

combination of butyrolactone/benzycyanide/triethylenediamine) which 

are commercially available and may be used to reconstitute the 

characteristic odor. 

Supported by NIH R01 DC 03704 to PD


ODOR CONDITIONING AND THE STRESS RESPONSE 

Maute C. 1, Dalton P. 1, Michele G. 1 1Monell Chemical Senses Center, 


The present study evaluated the degree to which an emotional state 

(i.e. stress or relaxation) initially experienced in the presence of a novel 

odor could later be elicited by the odor alone. Evaluations of both 

subjective (self-reported stress, health symptoms and mood) and 

objective (salivary cortisol) indices of stress demonstrated the efficacy 

of the Trier Social Stress Test (TSST) as a stress manipulation. Further, 

salivary cortisol levels revealed that subjects who were administered the 

(TSST) in the presence of a novel odor were more stressed upon reexposure 

to that odor than they were upon re-exposure to a different 

odor that had been paired with relaxation instructions. This apparent 

ability to induce stress below the level of awareness and its relevance to 

odor-conditioned stress responses as a potential mechanism underlying 

persistent aftereffects of trauma and odor-associated syndromes, such as 

multiple chemical sensitivity, will be discussed. 

Supported by DAMD17-01-2-0782 


THE IMPACT OF MALINGERING ON THREE MEASURES OF 

OLFACTION 

Bailie J.M. 1, Rybalsky K. 1, Horning K.A. 1, Hoffman S.M. 1, Gesteland 

R.C. 2, Frank R.A. 1 1Psychology, University of Cincinnati, Cincinnati, 

OH; 2Cell Biology, University of Cincinnati, Cincinnati, OH 

Experts on the sense of smell are occasionally asked to evaluate 

olfaction in forensic cases. Since it has been estimated that the faking of 

a physical injury, sensory or cognitive loss (known as malingering) 

occurs in as many as one out of six of these cases, it is valuable to have 

a measure of olfaction that is resistant to malingering. The Sniff 

Magnitude Test (SMT) is a newly-developed measure of olfactory 

function that uses sniffing responses to assess the sense of smell. The 

SMT may be resistant to malingering because it has low difficulty and 

at the same time it is not obvious to a typical patient how an olfactory 

loss is feigned. A total of 120 subjects were randomly assigned into 

four groups: a control group that received the standard administration of 

each olfactory test, Malingering Group 1 that received instruction to 

fake an olfactory loss but was not provided further instructions, 

Malingering Group 2 that was told to fake a loss and was given 

information about what each test measures, and Malingering Group 3 

that was told to fake a loss and was coached on how to appear anosmic 

on each of the three tests. The SMT was compared to two traditional 

tests- PEA odor threshold and performance on the UPSIT. Results are 

discussed in terms of the impact of test information on feigning an 

olfactory loss and the resistance of each test to malingering. This 

project supported by NIH SBIR grant DC04139, R. C. Gesteland, PI. 

30 


UNILATERAL OLFACTORY THRESHOLDS IN A 

CHEMOSENSORY CLINICAL POPULATION 

Cowart B.J. 1, Pribitkin E. 2, Rosen D. 2, Klock C. 1, Laflam T. 1 1Monell 

Chemical Senses Center, Philadelphia, PA; 2Otolaryngology-Head & 

Neck Surgery, Thomas Jefferson University, Philadelphia, PA 

Although unilateral (UNI) testing of olfactory threshold sensitivity is 

routinely performed in many chemosensory clinics to supplement 

bilateral (BI) tests, few studies have addressed the usefulness of these 

additional measures in either characterizing individual patients or 

providing insight into general characteristics of olfactory dysfunction. 

We report findings from 195 non-anosmic patients presenting to the 

Monell-Jefferson Taste & Smell Clinic who underwent both BI and 

UNI tests of thresholds for phenylethyl alcohol (PEA); BI and UNI 

thresholds for pyridine (PYR) were also obtained from a subset (n=73). 

37.4% of patients showed a left(L)-right(R) difference of at least one 

log step in PEA threshold concentration (v/v), but only 54.8% of those 

also showed a directionally consistent L-R difference in PYR 

thresholds. The presence of a UNI difference was not related to either 

degree of bilateral dysfunction or etiology; however, UNI testing did 

enable the identification of an olfactory problem in 15 patients whose 

BI testing yielded no evidence of abnormality. In contrast to what has 

been reported in largely non-clinical populations, patients´ best UNI 

thresholds for PEA were significantly poorer than their BI thresholds. 

Interestingly, however, this effect interacted with the presence of a L-R 

difference, being evident only in patients with comparable L-R 

thresholds. Thus bilateral facilitation of olfactory threshold sensitivity 

may occur in dysfunction when the two nostrils are similarly affected. 

Supported by NIH grant P50 DC00214. 


CLINICAL EVALUATION OF THE SNIFF MAGNITUDE TEST 

Frank R.A. 1, Seiden A. 2, Bailie J. 1, Rybalsky K. 1, Gesteland R.C. 3 

1Psychology, University of Cincinnati, Cincinnati, OH; 2Otolaryngology 

and Maxillofacial Surgery, University of Cincinnati, Cincinnati, OH; 

3Cell Biology, Univ of Cincinnati, Cincinnati, OH 

The Sniff Magnitude Test (SMT) is a newly developed olfactory 

measure that examines sniff patterns to assess smell function. Its utility 

has been assessed in children, university students, and older adults 

where it has proven to be a reliable measure that is strongly correlated 

with the UPSIT and odor threshold tests. This project examined the use 

of the SMT in a clinical setting. 44 otolaryngology patients completed 

the UPSIT and SMT during a visit to an ENT clinic in Cincinnati, Ohio. 

Patients who came to the clinic for olfactory complaints were compared 

to patients that came in for sinus-related problems and patients with 

hearing-related complaints. It was predicted that the olfactory complaint 

group would perform more poorly than the sinus and hearing groups on 

both the UPSIT and SMT. Patients with complaints about the sense of 

smell performed significantly worse on both the UPSIT and SMT 

compared to the sinus patients [F(1, 30) = 9.89, p< .005 and F (1, 33) = 

9.90, p < .005, respectively]. This was also the case for the participants 

who had hearing complaints [F(1, 26) = 25.083, p < .001 and F(1, 29) 

=12.36, p < .001, respectively]. There was no difference between the 

sinus and hearing patients on the two olfactory tests. These results 

demonstrate the utility of the SMT in a clinical setting and support 

additional studies of its use in other clinical conditions where olfactory 

deficits are a concern. This project supported by NIH SBIR grant 

DC04139, R. C. Gesteland, PI.


THE INFLUENCE OF ODOR PLEASANTNESS & IRRITATION 

ON THE SNIFF MAGNITUDE TEST 

Rybalsky K. 1, Bailie J. 1, Frank R.A. 1, Gesteland R.C. 2 1Psychology, 

University of Cincinnati, Cincinnati, OH; 2Cell Biology, Univ of 

Cincinnati, Cincinnati, OH 

The Sniff Magnitude Test (SMT) measures olfactory function based 

on the reduction of the size of a sniff in response to an odor. In the past, 

malodors have been successfully utilized to trigger sniff reduction. 

Experiments were conducted to assess the use of pleasant odors and to 

address concerns about possible irritation associated with the odorants 

being used with the SMT. 119 university students were tested in 3 

experiments. The stimuli included one malodor (methylthiobutyrate or 

MTB) and two pleasant odors, strawberry flavor (STR) and isoamyl 

acetate (AA). In Experiment 1, STR (1%v/v) suppressed sniffs by 37%. 

STR was then compared with MTB (3% v/v) and the results indicated 

that MTB suppressed sniffs by 46%, similar to but significantly more 

than STR (p < .05). In Experiment 2, assessment of sniff magnitude to 

MTB (1% v/v) and AA (1% v/v) yielded results similar to the STR. 

While sniff suppression to AA was effective (44%), participants 

suppress more to the MTB stimulus (51%, p < .05). Experiment 3 

assessed irritation and possible trigeminal sensitivity to MTB and AA. 

This was achieved using a nasal lateralization technique. It was 

demonstrated that neither MTB nor AA possess trigeminal components 

at the concentrations tested. The results from these studies support the 

use of both pleasant and unpleasant odors in the SMT and also allay 

fears about the potentially confounding role that trigeminal stimulation 

plays in the test. This project supported by NIH SBIR grant DC04139, 

R. C. Gesteland, PI. 

122 Slide [ ] Clinical Evaluation and Consumer Research 

INFLUENCES OF AGE AND SEX ON A 

MICROENCAPSULATED ODOR MEMORY TEST 

Choudhury E. 1, Moberg P. 2, Doty R. 3 1School of Dental Medicine, 

University of Pennsylvania, Philadelphia, PA; 2Department of 

Psychiatry, Neurology, and Otorhinolaryngology, University of 

Pennsylvania Medical Center, Philadelphia, PA; 3Smell and Taste 

Center, Department of Otorhinolaryngology, University of 

Pennsylvania Medical Center, Philadelphia, PA 

While influences of such variables as age and sex are well 

established for most standardized tests of odor identification and 

detection, this is not the case for tests of odor memory. In this study, 

231 non-smoking men and women, ranging in age from 10 to 68 years, 

were administered a standardized 12-item delayed match-to-sample 

micro-encapsulated odor memory test (OMT). Anosmics were excluded 

from the study. Each participant was asked to smell a target odor after 

its release from a micro-encapsulated odorant pad and then, after a 

delay interval of 10, 30, or 60 seconds, to pick the target from a 

similarly presented set of four odors, three of which were foils. 

Backward counting by threes was required during the delay intervals in 

an effort to minimize semantic rehearsal. Overall OMT scores were 

higher for women then for men, and decreased, in each sex, as a 

function of age in a manner similar to the age-related decline observed 

in tests of odor identification and detection. Performance did not change 

as a function of delay interval. A significant correlation between the 

overall OMT test scores and scores on the University of Pennsylvania 

Smell Identification Test were observed for women, but not for men, in 

accord with the notion that women may be more likely to employ 

semantic cues in their strategies to remember odors. The findings are 

discussed in light of the complexities of the construct of odor memory. 

This research was supported, in part, by the following grants from the 

National Institutes of Health, Bethesda, MD: PO1 DC 00161, RO1 DC 

04278, RO1 AG 17496 and RO1 MH 63381. 

31 


USE, HANDLING AND ASSESSMENT OF PERFUMES 

DEPENDING ON BRAND NAME AND PACKING 

Buschmann-Maiworm R. 1, Henkel M. 2, Schurian W. 2 1Dept. of 

Psychology, University of Muenster, Münster, Germany; 2University of 

Muenster, Muenster, NRW, Germany 

The experiment investigates how the image of a perfume influences 

its assessment and handling. 

Three perfumes with different images, designed for different age 

groups, were tested. In a pilot study 130 subjects rated the general 

image of 10 different well known perfumes (e.g. age and style of users, 

wish to buy it). 

In the main experiment Chanel 5, Naomagic, Kölnisch Wasser were 

used. Each perfume was tested in its own bottle and packing and in the 

bottles of the other two. As a result we have 9 experimental conditions. 

225 women assessed the perfumes in 3 conditions in random order on 

bipolar rating scales while they were videotaped. The handling of the 

packing and the bottle were analysed (e.g. for duration of touching). 

Categorised for behavioural analysis were 4 ways of smelling the 

perfume: applying on a paper strip, applying on skin, smelling at the 

bottle, smelling at cap. Trials using Kölnisch Wasser were the shortest. 

The odor of the perfumes (Naomagic, Kölnisch Wasser and Chanel 5) 

in the bottle of Naomagic were much longer faned. The handling of the 

packing of Naomagic was longer than of Kölnisch Wasser. Kölnisch 

Wasser was rated as moderate pleasant. It was significantly rated as 

more pleasant in the packing of Naomagic and Chanel 5 than in its own 

package. 

124 Slide [ ] Odorant Receptors & Transduction 

ORGANIZATION OF CHEMOSENSORY SIGNALING 

COMPONENTS IN LIPID RAFTS 

Van Houten J. 1, Weeraratne S. 1, Chandran S. 1, Yano J. 1 1Biology, 

University of Vermont, Burlington, VT 

Glycosyl phosphatidylinositol (GPI) anchored proteins are tethered to 

the cell surface and function as receptors that generally activate tyrosine 

kinases to initiate signal transduction pathways in axon guidance or Tcell 

activation, among other functions. These proteins are characteristic 

of in lipid rafts, lipid domains that are enriched in glycosphingolipids 

and cholesterol and signal transduction proteins. At least one 

Paramecium receptor for folate is GPI anchored and likely to be in lipid 

rafts. Another component of the signal transduction pathway, the 

plasma membrane calcium pump (PMCA), is enriched in lipid rafts in 

other systems, and shows the hallmarks of lipid raft association in 

Paramecium. Fluorescence microscopy shows that the GPI anchored 

proteins, including the folate receptor, co-localize with PMCAs and 

basal bodies, consistent with the localization of these proteins at the 

bases of cilia. We are using cholera toxin to localize the gangliosides in 

rafts. In a separate approach to lipid rafts, we use gradients to separate 

membrane fractions by density, with lipid rafts and their proteins 

characteristically populating the lighter fractions. Raft fractions are 

those with gangliosides, cholesterol and GPI anchored proteins. There 

are light density fractions of the Paramecium membranes that include G 

proteins, the folate receptor, other GPI anchored proteins, the PMCAs. 

In a third approach, we remove cholesterol from the whole cell 

membranes and note that the cells are defective in their chemo-response 

to folate. Varied approaches help us to examine the role of lipid rafts 

and other Triton X-100 insoluble components, such as the cytoskeleton, 

in chemoresponse. GM 59988, DC 00721 and the Vermont Cancer 

Center.


DNA-BASED FLUORESCENT CHEMOSENSORS FOR DIRECT 

DETECTION OF VOLATILE COMPOUNDS IN AN 

ARTIFICIAL NOSE 

White J.E. 1, Williams L.B. 1, Atkisson M.S. 2, Kauer J.S. 1 1Neuroscience, 

Tufts University School of Medicine, Boston, MA; 2CogniScent, inc., 

Weston, MA 

As reported previously (White et al., 2002, AChemS XXIV), we are 

developing a portable artificial olfactory system to detect and 

identify volatile compounds in the ambient environment. In a manner 

based directly on animal behavior, the device actively samples air via 

pulsatile sniffing. Air samples are drawn over an array of 

broadly-responsive, optically-based chemical sensors, which are used 

to detect and discriminate odorants in the sample. Device function 

thus depends directly on the sensitivity and diversity of the sensors 

in the array. Biopolymers, particularly nucleic acids, are attractive 

for building sensors of great variety and wide utility. This is 

because of the tremendous combinatorial complexity made possible 

by constructing them from sequences of just a few building blocks. We 

have found that dye-labeled DNA sensors, dried onto a substrate, 

differentially respond to volatile chemical compounds. To our 

knowledge, this is the first time that solid phase DNA-based sensors 

have been used for directly detecting small, vapor phase molecules. 

Furthermore, our experiments indicate that Cy3-labeled, single- strand 

DNA sequences of similar length but different base sequence can 

respond differently to the same odorant set. These observations 

suggests that "sensor discovery" via high throughput screening of 

large-scale DNA-based sensor libraries may be possible, thereby 

providing a rapid means to easily identify sensors that are optimized 

for defined odorant detection tasks. Supported by NIDCD and NSF. 

32 


MAKING SENSE OF OLFACTION THROUGH MOLECULAR 

MODELING 

Floriano W.B. 1, Hall S. 1, Leonard O. 2, Hummel P.A. 1, Vaidehi N. 1, 

Goddard W.A. 1 1Materials and Process Simulation Center, California 

Institute of Technology, Pasadena, CA; 2University of California - 

Berkeley, Berkeley, CA 

We used the MembStruk first principles computational technique to 

predict the three-dimensional (3D) structure of ten mouse olfactory 

receptors (S6, S18, S19, S25, S46, S50, S1, MOR-EV, MOR-EG, and 

MI7) for which experimental odorant recognition profiles are available. 

We used the HierDock method to scan each predicted OR structure for 

potential odorant binding site(s), and to calculate binding energies of 

each odorant in these binding sites. The calculated binding affinity 

profiles correctly identify the chemical classes recognized 

experimentally by each OR, validating the predicted 3D structures and 

binding sites. Correlation between calculated binding affinity and 

elicited response is also found within each chemical class. However the 

cutoff response/no-response is not always well defined. 

For each of the ten ORs, the binding site is located between TMs 3 

through 6, with contributions from EC loops 2 and 3. In particular, we 

find six residue positions in TM3 and TM6 to be consistently involved 

in odorant binding. These positions are consistent with mutation data on 

ligand binding for other GPCRs and sequence hypervariability studies 

for ORs. 

Amino acid patterns associated with the recognition of chemical 

classes were defined using the predicted binding modes. These 

sequence fingerprints were used to probe the alignment of 869 OR 

sequences from the mouse genome in order to identify other ORs 

matching each fingerprint. 

This research was initiated with support by an ARO-MURI grant 

(Dr. Robert Campbell) and completed with finding from NIHBRGRO1- 

GM625523, NIH-R29AI40567, and NIH-HD36385. The computational 

facilities were provided by a SUR grant from IBM and a DURIP grant 

from ARO. 


THE MULTIFACETED RECEPTORS OF THE HUMAN NOSE 

Lancet D. 1, Alony R. 1, Atarot T. 1, Ben-Asher E. 1, Feldmesser E. 1, Gilad 

Y. 1, Khen M. 1, Man O. 1, Menashe I. 1, Olender T. 1, Stern S. 1 1Molecular 

Genetics, Weizmann Institute, Rehovot, Israel 

Human olfactory receptor (OR) genes are highly multifaceted, as 

manifested at several different levels. This is documented in the 

updated Human Olfactory Receptor Data Exploratorium (HORDE 

version 40, http://bip.weizmann.ac.il/HORDE/), which contains 853 

entries. One dimension of diversity spans a continuum between intact 

ORs and definite OR pseudogenes. To probe the undecided cases, we 

have devised methods to identify subtle deviations from shared motifs. 

Positional departures of initiation and stop codons may indicate inactive 

ORs. Second generation rhodopsin-based homology models provide 

new clues to sequence positions essential for functionally intact 

structure, including helix-kinking residues. A new algorithm, based on 

paralog-orthologs comparisons for three mammalian species (human, 

mouse and dog), allowed us to identify potential odorant contact 

residues. These harbor maximal intra-species variability, but also 

constitute additional targets for inactivating mutations. Another 

dimension of diversity is inter-individual variability, generated by 

single nucleotide polymorphisms that occur at pseudogenizing sequence 

positions. This results in a personal genetic “bar-code”, whereby every 

human individual has a different combination of intact and inactive 

ORs. These “segregating pseudogenes” are likely key determinants of 

specific anosmia. Finally, OR gene diversity is probed at the 5´ 

untranslated exon sequences by computer-based and experimental 

approaches. This may shed light on presumed roles of upstream 

segments in OR messenger RNA stability and translation.


MOLECULES THAT REGULATE TRANSLOCATION AND 

FUNCTION OF MAMMALIAN ODORANT RECEPTORS 

Saito H. 1, Matsunami M. 1, Roberts R. 1, Chi Q. 1, Matsunami H. 1 1MGM, 

Duke University, Durham, NC 

Progress in understanding olfactory coding requires knowing ligand 

specificity of odorant receptors (ORs). It has been difficult to examine 

ligand-binding specificity of mammalian ORs in heterologous cells, 

mainly due to poor plasma membrane trafficking of ORs in these cells. 

Using a set of cDNA clones that are expressed by olfactory neurons, we 

have screened and found three genes that induce cell surface expression 

of ORs when expressed in HEK293T cells. We named them REEP1, 

for Receptor Expression Enhancing Protein 1, RTP1 and 2, for 

Receptor Transporting Protein 1 and 2, respectively. All three proteins 

contain a single putative transmembrane domain and they are 

specifically expressed by the olfactory neurons in the olfactory 

epithelium. These proteins are associated with OR proteins, and 

enhance activation of OR by odorants. Using a cell line expressing 

these genes, we have identified new mouse ORs responding to aliphatic 

odorants. Our results suggest that REEP1, RTP1 and 2 have important 

roles in trafficking of ORs and provide an efficient system to 

investigate OR-odorant interaction. 


THE ROLE OF ODOR RECEPTORS IN ODOR CODING 

Hallem E.A. 1, Ho M.G. 1, Carlson J.R. 1 1MCDB, Yale University, New 

Haven, CT 

We are undertaking a large-scale analysis of Drosophila odor 

receptors. The Or gene family contains ~60 members, which are 

expressed in at least 35 functional classes of olfactory receptor neurons 

(ORNs). We are examining the functions of odor receptors using an 

“empty” ab3A antennal ORN (∆ab3A) that lacks its endogenous odor 

receptors as an in vivo expression system. Individual receptors are 

introduced into the empty ORN (∆ab3A:OrX) and odor response is 

assayed electrophysiologically. We are establishing a receptor-toneuron 

map by matching the odor response spectra of ∆ab3A:OrX 

ORNs to the odor response spectra of wild-type ORNs. We have found 

that the odor receptor dictates not only the odor response spectrum, but 

also the signaling mode (excitation v. inhibition) and the response 

dynamics of the ORN in which it is expressed. Different receptors, 

when expressed in the same ORN and given the same odorant stimulus, 

can confer responses that differ in signaling mode. Moreover, an 

individual receptor can confer responses of different modes to different 

odorants in the same ORN. The results thus show that odor receptors 

contribute to multiple aspects of odor coding in Drosophila ORNs, and 

they suggest a model for odor receptor transduction. Not only can 

multiple receptors function in an individual ORN, but an individual 

receptor can function in multiple ORNs, suggesting a broad 

compatibility among receptors and ORNs. Finally, we express two 

odor receptors from the malaria vector mosquito Anopheles gambiae in 

Drosophila and find that the female-specific receptor AgOr1 responds 

to 4-methylphenol, a component of human sweat. 

33 

Supported by NIH DC04729 and an NSF graduate fellowship. 


THE HOR17-4 SIGNALING SYSTEM – ONE RECEPTOR, 

DUAL CAPACITY 

Spehr M. 1, Schwane K. 1, Barbour J. 1, Riffell J.A. 2, Heilmann S. 3, 

Gisselmann G. 1, Hummel T. 3, Zimmer R.K. 2, Neuhaus E.M. 1, Hatt H. 1 

1Ruhr-Universität Bochum, Bochum, Germany; 2biology, University of 

California, Los Angeles, CA; 3University of Dresden, Dresden, 

Germany 

A repertoire of mammalian olfactory receptor (OR) genes are 

predominantly expressed in spermatozoa. One of these receptors, 

named hOR17-4, is attributed an important role in human sperm 

physiology by mediating directed chemotactic movement in vitro. 

The underlying molecular mechanisms transducing OR ligand 

binding into flagellar motion remain obscure. Here, we show that sperm 

OR activation is coupled to a membrane-bound adenylyl cyclase 

(mAC). Odorant-induced Ca2+ signaling, chemotaxis, and 

chemokinesis are completely abolished by a specific inhibitor of mACs. 

Identifying membrane proteins in human sperm via mass spectometry, 

we show expression of specific receptors, G-proteins, and mACs. Their 

spatial distribution patterns largely correspond to the spatiotemporal 

character of odorant Ca2+ signals. Thus, our data link mAC activation 

to human sperm chemotaxis. 

Whether sperm ORs are functionally restricted to reproductive issues 

or additionally perform their “conventional” task in olfaction is a 

longstanding question. Therefore, we also investigate hOR17-4 

expression in human olfactory tissue adopting. Our results suggest that 

the same human OR protein is similarly utilized to fulfill chemosensory 

functions in such diverse cell types as spermatozoa and olfactory 

sensory neurons. 


MECHANISMS OF ODOR RECEPTOR GENE CHOICE 

Ray A. 1, Shiraiwa T. 1, Goldman A. 1, Van Der Goes Van Naters W. 1, 

Carlson J. 1 1MCDB, Yale University, New Haven, CT 

Little is known about how individual neurons select which Or genes 

to express. The Or gene family in Drosophila consists of ~60 members, 

most of which are expressed either in the antenna or the maxillary palp, 

but not both. 

We have used bioinformatics to identify cis -regulatory elements 

important for Or gene choice in the maxillary palp. Among several 

motifs that are over-represented upstream of Or genes, one, 

CTA(N) 9 TAA, is found within 500 bp upstream of Or genes expressed 

in the maxillary palp. We have found by mutational analysis that this 

motif is necessary for expression of Or genes in this organ. A second 

over-represented motif among maxillary palp genes is CTTATAA, and 

we have found evidence that this motif is a negative regulatory element 

that mediates repression of palp Or genes in the antenna. 

What information specifies the particular neuron class in which a 

receptor is expressed? A pair of Or genes, Or85e and Or33c, is coexpressed 

in the pb2A neurons of the palp. We have identified 3 motifs 

shared between the upstream sequences of these two co-regulated 

genes, but not by other palp genes. To identify neuron-specific 

regulatory motifs for the remaining palp Or genes, we have compared 

the Or upstream regions with those of their D. pseudoobscura 

orthologs. This approach has identified several additional gene-specific 

conserved elements. 

A second mechanism is used to achieve co-regulation of two genes in 

another neuron, pb2B. Two clustered Or genes, Or46a and Or46b, are 

transcribed as a bicistronic message in this neuron. We are testing the 

activity of a putative IRES, and the functional significance of the co-

expression. 


REGULATION OF ODORANT RECEPTOR EXPRESSION 

Reed R.R. 1, Lewcock J.W. 2 1Molecular Biology and Genetics, 

HHMI/Johns Hopkins University, Baltimore, MD; 2Molecular Biology 

and Genetics, Johns Hopkins University, Baltimore, MD 

The expression of a single odorant receptor (OR) in each olfactory 

neuron from a repertoire of more than 1000 genes is essential for odor 

coding and axonal targeting. The genes encoding these receptors each 

possess a simple genomic structure and in several cases, small DNA 

segments surrounding the transcription initiation sites are sufficient to 

direct expression of reporters in a pattern that mimics the endogenous 

genes. One remarkable aspect of this gene regulation is that each 

olfactory neuron expresses OR protein from only one allele of this 

large, dispersed gene family. We have used targeted transgenesis, 

insertion of defined DNA constructs at specific location in the genome 

to identify a new role for OR protein as an essential regulator in the 

establishment of mono-allelic OR expression. OR-promoter driven 

reporters expresses in a receptor-like pattern, but unlike a native OR, 

are co-expressed with an additional OR allele. Expression of a 

functional OR from the identical promoter eliminates expression of 

other OR alleles. The presence of an untranslatable OR coding 

sequence in the mRNA is insufficient to exclude expression of a second 

OR. Together, these data identify the OR protein as a critical element in 

a feedback pathway that regulates odorant receptor selection. Current 

efforts in the laboratory are focused on elucidating the nature of the 

feedback signal and the mechanisms that lead to selective receptor 

expression. 

Supported by grants from NIDCD to R. R. 

133 Symposium [ ] The Ins and Outs of Sensory Cilia 

WHAT THE CHLAMYDOMONAS FLAGELLUM IS 

TEACHING US ABOUT SENSORY CILIA 

Witman G.B. 1 1Cell Biology, University of Massachusetts Medical 

School (Worcester), Worcester, MA 

Both motile cilia and non-motile cilia, including mammalian primary 

cilia, are sensory organelles that display receptors and relay signals 

about the extracellular environment to the cell body. The unicellular, 

biflagellate green alga Chlamydomonas reinhardtii has provided an 

essential foundation for understanding this important ciliary function. 

A notable example is the recent discovery and characterization of 

intraflagellar transport (IFT) in Chlamydomonas. IFT is a process in 

which flagellar precursors are actively moved into the flagellum and out 

to its tip, where axonemal assembly occurs; disruption of this process 

blocks flagellar assembly. Genetic and biochemical studies in 

Chlamydomonas have elucidated the molecular motors and other 

components of the IFT system; all of these proteins have homologues in 

other ciliated organisms, including C. elegans, D. melanogaster, and 

mammals. Because IFT is necessary for ciliary assembly, mutation of a 

gene encoding a mouse homologue of a Chlamydomonas IFT protein 

disrupts assembly of primary cilia, providing a valuable tool for testing 

the function of these widespread organelles (see abstract by G. Pazour). 

Although primary cilia cannot be isolated, Chlamydomonas flagella can 

be readily purified in amounts sufficient for biochemical analysis. An 

ongoing proteomic analysis of the Chlamydomonas flagellum is 

revealing numerous conserved proteins that are likely to be involved in 

sensory processes. The mammalian homologues of these proteins are 

prime candidates for carrying out sensory reception and signal 

transduction in the primary cilium. Supported by NIH GM 30626. 

34 


PROBING THE FUNCTION OF MAMMALIAN PRIMARY 

CILIA BY ANALYSIS OF THE TG737 MOUSE 

Pazour G.J. 1 1Molecular Medicine, University of Massachusetts 

Medical School (Worcester), Worcester, MA 

Most mammalian cells have a non-motile primary cilium projecting 

from their surface. The importance of these organelles to mammalian 

health and development has been highlighted by recent analysis of the 

Tg737 mouse. This mouse has a mutation in the gene encoding the 

IFT88 subunit of the intraflagellar transport particle (Pazour et al., J. 

Cell Biol. 151:709-718) and develops polycystic kidney disease (PKD) 

(Moyer et al., Science 262:1329-1333) and other disorders. The Tg737 

mutation causes ciliary assembly defects in the kidney and other organs. 

These ciliary defects are likely to be the primary cause underlying the 

PKD and other diseases seen in the animal. 

We hypothesize that primary cilia are serving as organizing centers 

for sensory receptors and signaling proteins. In support of this, we and 

others have shown that the polycystins are localized on kidney primary 

cilia. The polycystins are membrane proteins thought to sense the state 

of the kidney epithelium and control proliferation and differentiation of 

these cells. Polycystin mutations cause excess cell proliferation in 

kidney nephrons resulting in adult onset PKD in humans. The ciliary 

assembly defect probably causes PKD by disrupting the localization of 

the polycystins. 

It is likely that all primary cilia serve similar functions in organizing 

receptors and pathways to monitor extracellular parameters that are 

important to the cell´s physiology. 

Work in my laboratory is funded by the NIH (GM60992) and the 

Worcester Foundation for Biomedical Research. 


INTRAFLAGELLAR TRANSPORT MOTORS 

Scholey J.M. 1, Ou G. 1, Snow J. 1, Gunnarson A. 1 1Center for Genetics 

and Development and Section of Molecular and Cellular Biology, 

University of California, Davis, Davis, CA 

The assembly and function of sensory cilia depends upon 

intraflagellar transport (IFT), the bidirectional transport of 

macromolecular complexes called IFT-particles, along axonemal 

microtubules (MTs) between the base of the cilium and the distal tip. 

We are studying the role of IFT in the formation and function of the 

sensory cilia on the endings of chemosensory neurons within the 

nematode, C. elegans. These cilia serve as specialized compartments for 

concentrating the sensory signaling machinery that detects chemical 

cues in the environment and thereby play important roles in 

chemosensory behaviour. Our hypothesis is that IFT-particles 

contribute to ciliary function by carrying key components of the ciliary 

axoneme, the signaling machinery, and possibly signals themselves, 

between the base and the tip of the cilium, and that the transport of 

these particles depends upon the action of two anterograde motors, 

kinesin-II and OSM-3-kinesin and a retrograde motor, IFT-dynein. We 

will report our recent progress in using light microscopy, biochemistry, 

genomics and genetics to dissect the protein machinery that drives IFT 

in this system. 

Reference: Scholey JM, 2003, Intraflagellar Transport. Ann Rev. 

Cell Dev. Biol., 19, 423.

136 Poster [ ] Olfactory Development 

METAMORPHOSIS OF AN OLFACTORY SYSTEM: 

HORMONAL REGULATION OF GROWTH AND 

PATTERNING IN THE ANTENNAL IMAGINAL DISC OF THE 

MOTH MANDUCA SEXTA. 

Fernandez K. 1, Bohbot J. 1, Vogt R. 1 1Biological Sciences, University of 

South Carolina, Columbia, SC 

Peripheral olfactory systems of insects such as moths, bees, 

mosquitoes and flies undergo metamorphosis, transforming from a 

simple larval antenna to the highly complex adult antenna mediating 

diverse chemosensory behaviors. Adult antennae derive from imaginal 

discs which grow during the larval stage, and undergo neurogenesis and 

morphogenesis during the pupal stage. We are characterizing patterns 

of morphogenic and gene expression activities in the imaginal disc and 

early developing antenna to identify events which lead to the patterning 

of the adult antenna and the specific expression of genes (ORs, OBPs) 

by distinct classes of olfactory sensilla. This study focuses on the 

antennal disc; disc growth occurs during the final larval instar from a 

ring of tissue surrounding the base of the larval antenna. We have 

characterized the spatial patterns of disc growth using an antibody 

against phosphorylated histone H3 (mitotic marker) and have 

characterized temporal and spatial specific expression of transcription 

factors Broad (metamorphosis) and distal-less (pattern) and the 

signaling protein Notch. Prior to pupation, the disc elongates and 

everts; we have shown this process is regulated by ecdysteroid 

hormones, and have observed a subsequent decline in total DNA 

content suggesting apoptotic events associated with this restructuring. 

These studies are establishing a foundation for identifying early events 

leading to the selection of specific chemosensory phenotypes of adult 

olfactory sensilla. 


IG-FAMILY CELL ADHESION MOLECULES IN THE 

DEVELOPING ANTENNAL LOBE OF THE MOTH MANDUCA 

SEXTA 

Gibson N.J. 1, Tolbert L.P. 1 1ARL Division of Neurobiology, University 

of Arizona, Tucson, AZ 

Establishment of the adult antennal (olfactory) lobe of Manduca 

sexta requires numerous choices regarding pathfinding, migration, 

fasciculation, and branching by olfactory receptor cells, glia, and 

antennal lobe neurons. We are investigating the roles played by cell 

adhesion molecules in this process. Using an antibody to Manduca 

neuroglian, a homolog of vertebrate L1, we find that receptor cell axons 

express neuroglian specifically in the axonal sorting zone and in the 

nerve layer surrounding the glomerular layer in the lobe; expression is 

notably absent in the glomerular neuropil. Neuropil-associated glia also 

label, and do so even in the absence of afferent axons. This suggests the 

possibility of a homophilic interaction between neuroglian molecules 

on receptor cell axons and antennal-lobe glia. Following sorting of 

axons into new fascicles, we find that only some fascicles are labeled, 

suggesting targeting-related specificity, as has been seen for fasciclin II. 

In a search for additional cell adhesion molecules, we have used an 

antibody against the Ig-domain of human NCAM and obtained strong 

labeling of antennal lobe neurons and glia, but not axons. Western blots 

using this antibody demonstrate a prominent band at 125 KDa, similar 

in size to vertebrate NCAM-120 and OCAM and distinguishing this 

protein from the other Ig-containing molecules known to occur in 

Manduca, fasciclin II and neuroglian. Supported by NIH DC2004598. 

35 


OLFACTORY RECEPTOR CELLS OF TRANS-SEXUALLY 

GRAFTED FEMALE ANTENNAE DETERMINE ODOR 

RESPONSES OF OUTPUT NEURONS IN THE ANTENNAL 

LOBE OF MALE MANDUCA SEXTA 

Reisenman C.E. 1, Stein H. 1, Christensen T.A. 1, Hildebrand J.G. 1 1ARL 

Division of Neurobiology, University of Arizona, Tucson, AZ 

The antennal lobe (AL) of the moth Manduca sexta contains a small 

number of sexually dimorphic glomeruli: the macroglomerular complex 

(MGC) in males and the large female glomeruli (LFGs) in females. The 

role of olfactory receptor cells (ORCs) in the formation of these 

glomeruli was demonstrated by trans-sexual transplantation 

experiments: sensory axons of a grafted male antenna induce formation 

of an MGC in a host female, while sensory axons of a grafted female 

antenna induce formation of LFGs in a host male. The odor-response 

properties of the induced glomeruli, however, are unknown. Using 

intracellular recording and staining techniques, we studied the 

properties of output neurons (PNs) in males with a grafted female 

antenna. To produce these gynandromorphs, one antennal disk from a 

2 nd -day 5 th -instar larva was excised and replaced by the corresponding 

disk from a female donor. 22% of animals had a normal female antenna 

(n=7) and an antennal nerve innervating the AL. We found that PNs 

arborizing in the induced LFGs (like latLFG-PNs in normal females) 

were more sensitive to (+) than to (-)linalool (n=3, 2 animals). 

Although not morphologically identified, we found 3 more presumptive 

PNs with the same odor specificity. The morphology of PNs 

innervating glomeruli outside the induced LFGs was similar to that of 

PNs in normal females (n=4). One of these PNs arborizes in a 

glomerulus next to the induced latLFG, and did not respond to antennal 

stimulation with either (+) or (-)linalool. These preliminary results are 

consistent with the hypothesis that ORCs confer specific odor-tuning 

characteristics to their glomerular targets. 

Supported by NIH/PEW


NO-MEDIATED SIGNALING FROM OLFACTORY 

RECEPTORS TO PERIPHERAL NERVE GLIA IN THE MOTH 

OLFACTORY PATHWAY 

Oland L.A. 1, Gibson N.J. 2, Tolbert L.P. 2 1A.R.L. Division of 

Neurobiology, University of Arizona, Tucson, AZ; 2Neurobiology, 

University of Arizona, Tucson, AZ 

In the developing olfactory (antennal) nerve of the moth Manduca 

sexta, the glia that populate the nerve arise in the antenna and migrate 

along the nerve. They reach the CNS/PNS interface region of the nerve 

several stages after the first axons have arrived and begin to ensheathe 

bundles of axons in the nerve. In recent in vitro studies, antennal nerve 

(AN) glia were found to advance readily along glial processes, and 

ORN axons were found to induce the AN glia to form multi-cellular 

arrays (Tucker and Tolbert, 2003). Array formation did not require 

direct ORN-AN glia contact, but occurred only in glia in close 

proximity to the axons, suggesting that the axons release a short-range 

diffusible signal. Evidence from previous studies of nitric oxide (NO) in 

developing Manduca indicated that a Ca ++ -dependent NO synthase is 

strongly expressed in the antenna (Nighorn et al., 1998), that the ORN 

axons express NO synthase during stages of axon ingrowth when the 

AN glia are populating the nerve (Gibson and Nighorn, 2000), and that 

NO regulates AN glial migration (Gibson et al., 2001). Current 

experiments test whether the formation of arrays by AN glia in vitro is a 

consequence of NO release by ORN axons. In co-cultures of ORN 

neurons and PN glial cells, glial arrays can by reduced by a NOS 

inhibitor. In cultures of AN glia only, NO donors can induce glial 

chaining. Our initial results suggest that NO signaling from the ORN 

axons may be involved in the normal developmental processes of AN 

glia elongation and migration. Supported by NIH-DC04598 to LPT. 


EXPRESSION PROFILES OF GENES REGULATED BY 

THYROID HORMONE IN THE NOSE OF XENOPUS LAEVIS 

Walworth E. 1, Burd G. 1 1Molecular and Cellular Biology, University of 

Arizona, Tucson, AZ 

In Xenopus, metamorphosis is initiated by rising levels of 

endogenous thyroid hormone (T ). During metamorphosis from tadpole 

3 

to frog, essentially every organ/tissue is remodeled and many new 

structures must be formed. The nose of Xenopus tadpoles contains two 

areas of sensory epithelium. At metamorphosis, one area is completely 

remodeled and a new, third area of sensory epithelium is formed de 

novo. Apoptosis, cell proliferation, remodeling of the extracellular 

matrix and cell differentiation all take place during this transformation. 

Previously by our laboratory, more than 125 gene fragments associated 

with metamorphosis in the frog nose were isolated and identified using 

representational difference analysis, including gene fragments known to 

be associated with all of the above cellular processes. In this study, 56 

of those genes were subjected to real time quantitative RT-PCR at 5 

different stages of development throughout metamorphosis. We found 

the expression levels of several of the T early response genes, 

3 

including Gene 12, transcription factors (nuclear factor I-B, TH/bZIP, 

TRβ) and an extracellular matrix remodeling enzyme (stromelysin 3), 

were elevated 3 to 57 fold in response to 48 hours of T treatment, and 

3 

expression remained elevated throughout metamorphic climax. The 

elevated levels of expression were visualized by in situ hybridization. 

Therefore, these genes which are known to participate in remodeling 

other tissues undergoing metamorphosis, also aid in remodeling the 

nasal capsule. Support: NIDCD #DC03905 

36 


DE NOVO DNA METHYL TRANSFERASES AND METHYL 

DNA BINDING DOMAIN PROTEINS IN OLFACTORY 

NEUROGENESIS 

Macdonald J. 1, Gin C. 1, Roskams A.J. 1 1Zoology, University of British 

Columbia, Vancouver, British Columbia, Canada 

Epigenetic Regulation (Silencing) of mammalian genomic DNA 

occurs when de novo methyltransferases (DNMTs) methylate sites in 

the mammalian genome to form targets for methyl-CpG binding 

domain proteins (MBDs). MBDs form repressor complexes that can 

directly repress promoters or modify chromatin structure by recruitment 

of histone deacetylases (HDACs). In the mouse olfactory epithelium, 

DNMT1, 2, 3a, and 3b are expressed in the OE from embryonic 

development through adulthood. DNMT3a and 3b expression is 

maximal in developing ORNs at peaks of neurogenesis. DNMT3b is 

expressed in presumptive globose basal cells, sustentacular cells, and 

cells migrating from the basal layer to the sustentacular layer in the 

E16.5 OE. DNMT3b is primarily expressed (with PCNA) in actively 

proliferating cells and may thus play a role in ORN progenitor cell 

cycle exit or neuronal fate choice. DNMT3b+/PCNA+ cells migrating 

from the basal layer are NST negative and likely represent an 

alternative lineage to the neuronal lineage. DNMT3a is expressed in 

post-mitotic immature ORNs and a subset of mature ORNs and may 

play a role in lineage restriction and induction of terminal ORN 

differentiation in non-proliferating neuro-precursors. Expression of 

HDAC2 is induced at the earliest stages of neuronal differentiation and 

is down-regulated at terminal differentiation of ORNs. A small 

percentage of DNMT3b positive cells begin to express HDAC2, while 

the majority of DNMT3a positive cells express HDAC2. This 

continuum of HDAC2 expression suggests that it may be appropriately 

expressed to mediate gene silencing responses to DNA methylation 

catalyzed by both DNMT3b and DNMT3a. 


MECHANISMS BY WHICH BDNF AND NGF ACT AND 

INTERACT WITH ATRIAL NATRIURETIC PEPTIDE TYPE-C 

TO PROMOTE PROLIFERATION OR DIFFERENTIATION OF 

OLFACTORY NEURONAL PRECURSORS. 

Simpson P.J. 1, Moon C. 1, Ronnett G.V. 1 1Neuroscience, Johns Hopkins 

University, Baltimore, MD 

Both BDNF and NGF promote the proliferation of a subset of 

olfactory neuronal precursor cells. Concurrent exposure to atrial 

natriuretic peptide type-C (CNP) inhibits this proliferation and 

promotes differentiation. Immunocytochemical analysis of cell cycle 

regulatory proteins shows that both BDNF and NGF increase levels of 

cyclin D1 and cdk4 although the mechanisms behind these increases 

differ. NGF also increases p27. Addition of CNP with neurotrophin 

inhibits increases in cyclin D1 and p27 while alternatively increasing 

levels of a variety of cell cycle inhibitory proteins, including p21. The 

profile and time course of this inhibitor expression varies between 

BDNF and NGF. Analysis of the mechanisms behind changes in cyclin 

D1 and p21 shows that inhibition of the MAPK pathway blocks 

alterations in cyclin D1 levels in response to either neurotrophins or 

neurotrophins with CNP. CNP however does not promote Erk1/2 

phosphorylation, suggesting that it may alter the specificity of MEK1/2 

signaling. Other signal transduction pathways are responsible for 

alterations in p21. Inclusion of cycloheximide results in an increase in 

p21 levels in response to neurotrophins and an increase in cyclin D1 

levels in response to neurotrophins with CNP. These results are 

mimicked by application of 26S proteosome inhibitors. This suggests 

that the switch between proliferation and differentiation is primarily 

regulated through reciprocal degradation of inhibitory or progressive 

cell cycle proteins with a requirement for protein synthesis. Supported 

by NIDCD 5RO3DC005704-02 (PJS).


ADULT OLFACTORY PROGENITOR CELLS GIVE RISE TO 

BOTH NEURONS AND NON-NEURONAL CELLS IN 

CULTURE 

Jang W. 1, Woo J. 1, Schwob J.E. 1 1Anatomy and Cellular Biology, Tufts 

University, Boston, MA 

Recent data, including transplantation of FACS-sorted cells, indicate 

that the adult olfactory epithelium (OE) retains mutipotent progenitors 

(MPPs) among the globose basal cell (GBC) population, which can be 

activated when reconstitution of the OE requires replacement of both 

neurons and non-neuronal cells. Not much is known about the 

regulation of progenitor cell capacity, and in vitro studies of 

multipotency are warranted. Dissociated epithelial cells were taken 

from mice exposed to MeBr gas (MeBr-OE) 40 hr prior to use. 

Harvested cells were plated either on uncoated or matrigel-coated 

surfaces and grown in complex, serum-rich medium or defined, serumfree 

medium. In serum-rich medium, regardless of coating, MeBr-OE 

gives rise to cultures that are heterogeneous: constituent cells, in 

aggregate, display the phenotypic characteristics of neurons (TuJ-1[+]), 

sustentacular cells (cytokeratin [CK]-18[+]), and horizontal basal cells 

(CK-5 or 14[+]). TuJ-1 (+) cells grow in a scattered fashion, while CKexpressing, 

epithelioid cells cluster together tightly. In serum-free 

medium, MeBr-OE generates only CK-18 or CK-5/14 (+) epithelioid 

islands. Our GBC markers GBC-2 and GBC-3 stain some, but not all, 

cells in the islands. Interestingly, cells grown on matrigel, regardless of 

serum, generate spheres that project above the surface to the dish. The 

ability to assay and manipulate adult MPPs in vitro will give us a better 

understanding of the mechanisms that regulate proliferation and 

differentiation, and may lead, eventually, to therapeutic applications. 

Supported by R01 DC02167 and R21 DC006517 

144 Slide [ ] Olfactory Development 

STUDIES OF OLFACTORY CELL LINEAGE AND 

DIFFERENTIATION USING AN IN VITRO NEUROSPHERE 

MODEL AND TIME-LAPSE VIDEOMICROSCOPY 

Cunningham A.M. 1, Marlicz W. 2 1Developmental Neurosciences 

Program, University of New South Wales, Sydney, NSW, Australia; 

2University of New South Wales, Sydney, NSW, Australia 

The mammalian olfactory neuroepithelium possesses a unique 

progenitor cell as it avidly supports neurogenesis throughout adulthood 

and is capable of reconstituting cells of neuronal and non-neuronal 

lineages after injury. Most evidence suggests this progenitor resides in 

the GBC layer and using retroviral lineage tracing Huard et al. (1998) 

found evidence supporting a multipotent progenitor capable of making 

GBCs, HBCs and sustentacular cells. To identify this cell in vitro we 

developed a culture system of olfactory progenitor cells. Turbinate 

tissue was taken from 48 hr old Wistar rat pups and putative progenitors 

enriched from a preparation of dissociated olfactory neurons 

(Cunningham et al. 1999). Clonal neurospheres formed from individual 

motile cells and made progeny of neuronal and sustentacular classes, 

based on immunocytochemical analysis for GBC-1, Olf-1, G , Type 3 

olf 

adenylyl cyclase and SUS-4. Double-labeling immunocytochemistry of 

young spheres revealed cellular heterogeneity, consistent with lineage 

specification occurring early in sphere development. Spheres passaged 

and generated secondary spheres although at lesser frequency than CNS 

neurospheres generated from forebrain. Our data is consistent with our 

having isolated in vitro a progenitor predicted to exist by Huard et al. 

(1998). Our system of clonal neurospheres provides a model of 

progenitor cell development that will allow better understanding of the 

mechanisms underlying olfactory neurogenesis. Supported by the 

Garnett Passe and Rodney Williams Memorial Foundation 

37 


STOCHASTIC YET BIASED EXPRESSION OF MULTIPLE 

DSCAM SPLICE VARIANTS BY INDIVIDUAL CELLS 

Chess A. 1, Daly M. 2, Neves G. 2, Zucker J. 2 1Biology, Massachusetts 

Institute of Technology, Cambridge, MA; 2Whitehead Institute, 

Cambridge, MA 

The Drosophila Dscam gene is essential for axon guidance and has 

38,016 possible alternative splice forms. This extraordinary diversity 

can potentially be used to distinguish cells. We have analyzed the 

Dscam mRNA isoforms expressed by different cell types and individual 

cells. The choice of splice variants expressed is regulated both spatially 

and temporally. Different subtypes of photoreceptors express broad yet 

distinctive spectra of Dscam isoforms. Single cell RT-PCR documented 

that individual cells express at least several different Dscam isoforms 

and allowed an estimation of the diversity that is present. For example, 

we estimate that each R3/R4 photoreceptor cell expresses 14-50 distinct 

mRNAs chosen from the spectrum of thousands of splice variants 

distinctive of its cell type. Thus, every cell´s Dscam repertoire is 

different from those of its neighbors providing a potential mechanism 

for the generation of unique cell identity in the nervous system and 

elsewhere. Prior studies by Zipursky and colleagues indicate an 

important role for the Dscam gene in controlling the proper targeting of 

olfactory receptor neurons. We are currently assessing the importance 

of the expression of distinct alternative splice forms by different 

olfactory neurons in axon targeting specificity. 


A PUTATIVE ROLE FOR MHCI IN THE AXONAL 

TARGETING OF THE MOUSE OLFACTORY SYSTEM 

Salcedo E. 1, Restrepo D. 1 1Cell and Developmental Biology, University 

of Colorado Health Sciences Center, Denver, CO 

The ability to smell offers a remarkable solution to the daunting 

challenge of discriminating between diverse chemical molecules. 

Investigation into the cellular and molecular mechanisms of 

mammalian olfaction has established the olfactory bulb as a primary 

processing unit that organizes the signaling from olfactory sensory 

neurons into a topographical sensory map. However, the molecular 

mechanisms establishing this sensory map remain to be elucidated. In 

the current study, we investigate the role that major histocompatibility 

complex class I molecules (MHCI) play in organizing this sensory map. 

Towards this end, we have used immunohistochemistry to demonstrate 

the expression of MHCI molecules in the main olfactory bulb (MOB). 

Additionally, we have examined mice that are severely deficient in the 

expression of MHCI on the surfaces of cells (TAP -/- ). By crossing these 

mice with a strain of mice that co-expresses Tau-LacZ with the P2 

olfactory receptor, we can visualize the axonal projection patterns of the 

P2 olfactory sensory neurons in a background deficient for the 

expression of MHCI molecules. After mapping the P2 glomeruli in the 

MOB of both wild-type and TAP -/- mice, we have uncovered subtle but 

statistically significant differences in the location and number of P2 

glomeruli.


CELL TYPES EXPRESSING OMP IN THE OLFACTORY 

EPITHELIUM OF LARVAL ZEBRAFISH 

Sakata Y. 1, Michel W.C. 1 1Physiology, University of Utah, Salt Lake 

City, UT 

The olfactory epithelium of zebrafish contained ciliated, microvillar 

and crypt-type sensory neurons. While there appears to be some overlap 

in specificity across the cell types the ciliated OSNs appear to respond 

preferentially to bile salts and the microvillar cells to amino acids. 

Recently, Celik et al (Euro. J. Neurosci. 15:798, 2002) reported the 

expression of GFP under the zebrafish OMP promoter was found 

primarily in ciliate OSNs but also found in cells with shorter and stouter 

dendrites, presumably microvillar cells. In the current investigation we 

produced a genetic construct with the zebrafish OMP promoter driving 

expression of eYFP to quantitatively examine the distribution of eYFP 

in the OSN populations of larval zebrafish. The zOMP promoter was 

cloned from genomic DNA using primers described by Celik et al 

(2002), ligated into an pEYFP vector (Clontech). The vector was 

subsequently linearized and injected into 1 cell stage zebrafish 

embryos. OMP promoter driven expression of eYFP was noted by 48 

hours. The transiently transfected embryos were reared for 48-72 hours 

post-fertilization, fixed and processed for whole embryo 

immunocytochemistry using the anti-GFP antibody. After 

immunostaining the embryos were embedded in Eponate plastic and 

sectioned for electron microscopy. Preliminary counts indicate that the 

majority of the eYFP expressing cells are ciliated OSNs but confirm the 

expression was also observed in some microvillar OSNs. Until a stable 

transgenic line is produced we cannot provide reliable estimates of the 

proportions of ciliated or microvillar OSNs expressing. Supported by 

NIH DC01418 and NS-07938. 


TYROSINE HYDROXYLASE-LIKE IMMUNOREACTIVE 

CELLS IN THE OLFACTORY TRACTS OF GOLDFISH 

Hansen A. 1, Finger T.E. 2 1University of Colorado Health Sciences 

Center, Denver, CO; 2Cell and Developmental Biology, University of 

Colorado Health Sciences Center, Denver, CO 

Goldfish possess a substantial population of tyrosine hydroxylase 

(TH)-like-immunoreactive cells within the olfactory tracts (OT) as well 

as TH-like-ir cells in the olfactory bulbs (OB). The TH-like-ir neurons 

in the OB have round cell bodies and large round nuclei with a single 

dendritic process extending towards the margin of the OB. These 

neurons were identified as a subset of granule cells (Alonso et al., 

1989). The nature and origin of the TH-like-ir cells in the OT are 

unknown. The aim of the present study was to clarify whether the THlike-ir 

cells are newly generated cells which migrate into the OB, or 

whether they are more mature cells that are stationary in the OT. 

Goldfish was chosen as a model since they have long OTs, and ample 

information is available as to anatomy, physiology, and behavior. 

BrdU-injections were used to visualize newly generated cells; and 

antibodies used to characterize the nature of the cells in question. The 

TH-like-ir cells in the OT are similar in shape to those in the OB, 

however, the tract cells are bipolar, extending one long process towards 

the OB and one towards the telencephalon. The majority of these cells 

occur in the medial OT, fewer in the lateral OT. One day after injection, 

BrdU-positive nuclei occur along the medial and lateral OTs. Six days 

after BrdU-injection, labeled nuclei are present at the whole length of 

the OTs and also in the OB. Further experiments are underway to test 

whether the TH-positive cells of the OT are equivalent to the rostral 

migratory stream of rodents. 

This study was supported by NIDCD grant RO1 DC033792 to J. 

Caprio and P30 DC04657 to D. Restrepo. 

38 


POSTNATAL CHANGES IN THE RAT MODIFIED 

GLOMERULAR COMPLEX: A QUANTITATIVE 

CYTOCHROME OXIDASE STUDY 

Meisami E. 1 1Molecular and Integrative Physiology, University of 

Illinois at Urbana-Champaign, Urbana, IL 

The modified glomerular complex (MGC) has been described as a 

set of glomeruli on the dorsomedial side of the rat olfactory bulb (OB), 

associated with suckling behavior in the neonate. We further explored 

the morphometric and anatomical features of MGC during postnatal 

development, using coronal series of cytochrome oxidase (CO) stained 

sections of the OB at postnatal ages of 1-, 3 -, 10- and 25 -days and 

analyzed with regard to lateral and medial distribution of the glomeruli, 

their size and number, and the anterior-posterior (AP) length of MGC. 

The MGC stained intensely for CO even in the newborn animal, 

compared to main OB glomeruli. In addition to the originally described 

medial complex, a lateral complex was also noted, particularly in rat 

pups 3 days and older. This complex had fewer glomeruli and was 

shorter than the medial complex, but its glomeruli were similar in size 

and stain intensity. Anteriorly the lateral and medial portions appear to 

fuse along the midline, forming an asymmetrical horseshoe structure. 

Total glomeruli number in the entire complex (medial and lateral) 

increased postnatally, from about 15 at birth to about 20 at 3 days, 40 at 

10 days, and about 70 at day 25. During the same period, mean 

glomerular diameter increased from about 60 mm at birth to about 85 

mm in the weanling. These changes were accompanied by marked 

increases in total glomerular volume. Results indicate that MGC is well 

developed at birth, but continues to develop postnatally in terms of 

number and size of its glomeruli, indicating possible olfactory functions 

of this complex in the weanling and older animals. 

Support: University of Illinois Research Funds 

150 Poster [ ] Odor Activation and Modulation 

OMP IS A MODULATOR OF CA2+ CLEARANCE PROCESSES 

IN MOUSE OLFACTORY RECEPTOR NEURONS (ORNS) 

Kwon H.J. 1, Leinders-Zufall T. 1, Zufall F. 1, Margolis F.L. 1 1Dept. 

Anatomy & Neurobiology, Program in Neuroscience, University of 

Maryland, Baltimore, MD 

Ca 2+ entry to ORNs is a well-studied event in chemosensory 

transduction. However, restoration of intracellular Ca 2+ levels to the 

pre-stimulus level is less well understood. Recent behavioral and 

electrophysiological analyses of OMP–null mice led us to hypothesize 

that OMP participates in the recovery phase of olfactory signaltransduction. 

To investigate this we compared Ca 2+ transients in ORNs 

of wild-type and OMP-null mice by activating various pathways to 

increase the cytoplasmic [Ca 2+ ]. KCl, 3-isobutyl-1-methylxanthine 

(IBMX), and caffeine were used to induce Ca 2+ influx from voltagegated 

Ca 2+ channels, cyclic-nucleotide gated channels, and intracellular 

Ca 2+ stores, respectively. Confocal laser images were recorded from 

dendritic knobs of mouse ORNs loaded with the Ca 2+ -indicator dye 

fluo-4 AM. In OMP-nulls in response to IBMX, the rate of Ca 2+ entry 

to reach peak was 5-fold slower, and to achieve half-recovery to basal 

level was 4-fold slower compared to controls. Following KCl 

depolarization, the OMP-null mice showed a 2-fold delay in the halfrecovery 

time of the Ca 2+ peak. Similar results were obtained following 

Ca 2+ store depletion by stimulating ryanodine receptors with caffeine. 

These results suggest that the cytoplasmic Ca 2+ clearance of ORNs is 

significantly impaired in the OMP-null mice. These data imply that 

OMP is a modulator of Ca 2+ extrusion or sequestration processes in 

ORNs. Characterization of the mechanism by which OMP modulates 

Ca 2+ flux in ORNs is under investigation. 

Supported by NIH DC03112 (FLM), NIH DC DC00347 (FLM, FZ), 

NIH DC003773 (TL-Z).


OMP: A CAUTIONARY TALE OF A GENE WITHIN A GENE 

Margolis J.W. 1, Munger S.D. 1, Zhao H. 2, Margolis F.L. 1 1Dept Anat & 

Neurobiology, University of Maryland School of Medicine, Baltimore, 

MD; 2Dept Biology, Johns Hopkins University, Baltimore, MD 

Expression of the olfactory marker protein gene (Omp) is very highly 

restricted to mature olfactory receptor neurons and vomeronasal 

receptor neurons in vertebrates. A related cDNA has been cloned from 

the snail Eobania vermiculata (Mazzatenta et al., 2002), suggesting that 

OMP is of broad phylogenetic distribution, distant evolutionary origin 

and functional significance. The detailed characterization of the OMP 

gene and protein has made it a desirable locus for genetic manipulation 

in the olfactory system. The Omp locus, including the intronless coding 

region for OMP as well as all its regulatory elements, spans about 12kb 

in the rodent genome. To our surprise, our recent in silico analysis of 

this genetic region has revealed that the mouse Omp locus is entirely 

contained within an ~ 16kb intron of the gene encoding the Calpain 5 

(Capn5) protease. The Omp and and Capn5 genes are similarly 

organized in the human, rat and Fugu genomes. These analyses beg a 

critical question: do the observed phenotypic alterations that result from 

genetic manipulations of the Omp locus reflect (1) a direct and accurate 

result of these manipulations or (2) an alteration in the splicing and/or 

expression pattern of Capn5? We will present data that address these 

concerns. 

Supported by NIH grants DC003112(FLM), DC005633(SDM), 

DC006178(HZ) 


RESPONSE PROFILES AND NARROWING SELECTIVITY OF 

OLFACTORY RECEPTOR NEURONS OF XENOPUS LAEVIS 

TADPOLES 

Manzini I. 1, Schild D. 1 1Department of Molecular Neurophysiology, 

University of Goettingen, Goettingen, Germany 

In olfactory receptor neurons (ORNs) of aquatic animals amino acids 

have been shown to be potent stimuli. Here we report on calcium 

imaging experiments in slices of the olfactory mucosa of Xenopus 

laevis tadpoles. We were able to determine the response profiles of 283 

ORNs to 19 amino acids, where one profile comprises the responses of 

one ORN to 19 amino acids. 204 out of the 283 response profiles 

differed from each other. 36 response spectra occurred more than once, 

i.e. there were 36 classes of ORNs identically responding to the 19 

amino acids. The number of ORNs that formed a class ranged from 2 to 

13. Shape and duration of amino acid-elicited [Ca2+ ] transients showed 

i 

a high degree of similarity upon repeated stimulation with the same 

amino acid. Different amino acids, however, in some cases led to 

clearly distinguishable calcium responses in individual ORNs. 

Futhermore, ORNs clearly appeared to gain selectivity over time, i.e. 

ORNs of later developmental stages responded to less amino acids than 

ORNs of earlier stages. [Supported by DFG:SFB 406 (B5) and by 

DFG:SPP Molecular Sensory Physiology] 

39 


RESPONSES OF OLFACTORY RECEPTOR NEURONS 

LACKING SPONTANEOUS ACTIVITY TO AMINO ACID 

STIMULI IN BLACK BULLHEAD CATFISH (AMEIURUS 

MELAS) 

Valentincic T. 1, Dolensek J. 1 1Department of Biology, University of 

Ljubljana, Ljubljana, Slovenia 

The cilia and microvilli of olfactory receptor neurons (ORNs) of 

freshwater fish are directly exposed to water containing few ions. We 

showed that non-spontaneously active ORNs respond to amino acid 

stimuli even when exposed for several hours to highly purified water 

(R>18.2 megaΩcm). Using extracellular platinum black electrodes, we 

recorded concentration dependent responses to 10 amino acid stimuli: 

L-nVal, L-Met, L-Ala, L-Leu, L-Ser, L-Lys, L-Val, L-Arg, L-Ile and L- 

Pro at 10-4 M. Five non-spontaneously active ORNs responded to LnVal 

(lowest threshold, 10-7 M) and L-Met only, and two ORNs 

responded to L-nVal and L-Val only. The only completely specialist 

cell responded to L-Ala. Additional extracellular recording sites were 

selected by moving the electrode and searching for a response to LnVal. 

At 15 such locations, responses to other amino acids were 

recorded. Responses to L-Met were observed at 13, to L-Ala at 9, to L- 

Ser at 9, to L-Leu at 7, to L-Val at 4, to L-Ile at 4, to L-Arg at 4, to L- 

Lys at 3 and to L-Pro at 2 locations. All recording locations were 

equivalent and situated along lamellae 2-7. The number of locations 

where responses to specific amino acid stimuli were observed correlates 

highly with the magnitude of the EOG responses (Spearman 

correlation, R=0.91; P


EFFECTS OF GNRH ON TIGER SALAMANDER OLFACTORY 

RECEPTOR NEURON RESPONSES TO AMINO ACIDS 

Yurchenko O. 1, Delay R. 2, Wirsig-Wiechmann C.R. 1 1Cell Biology, 

University of Oklahoma Health Sciences Center, Oklahoma City, OK; 

2Biology, University of Vermont, Burlington, VT 

To assess the role of the terminal nerve in olfaction we tested the 

hypothesis that gonadotropin-releasing hormone (GnRH) alters 

olfactory receptor neuron (ORN) responses to odorants. Recordings 

were made from acutely isolated ORNs of tiger salamanders using the 

loose patch-clamp technique and yielded data for 60 ORNs. Lglutamate 

and L-alanine singly and as a mixture (AA) were used as 

stimuli. Application of the AA mixture (both amino acids) evoked 

hyperpolarizing responses in 41% of ORNs and depolarizing responses 

in 12% of ORNs; 47% of ORNs did not respond the AA mixture. A 

hyperpolarizing response was dominant when L-alanine alone was 

used. L-glutamate evoked only hyperpolarizing responses. GnRH 

modulated chemosensory responses of ORNs. GnRH increased the 

amplitude of hyperpolarizing responses to the AA mixture and single 

amino acids. The effect of GnRH on depolarization could not be 

assessed due to few cells responding with depolarization. Of the 60 

neurons tested, 28 did not show a response to the AA mixture or 

individual amino acids. In these ORNs application of GnRH with AAs 

induced the appearance of excitatory or inhibitory responses. 

Application of GnRH alone never induced responses in ORNs. These 

results suggest that GnRH can modulate odorant sensitivity of ORNs 

and may play a role in governing the balance of information flow to the 

olfactory bulb. Supported by an Oklahoma Center for the Advancement 

of Science & Technology (OCAST) grant HR00-078 (CRW). 


GONADOTROPIN-RELEASING HORMONE (GNRH) 

MODULATES K+ CURRENTS IN TIGER SALAMANDER 


Park D. 1, Eisthen H.L. 1 1Zoology, Michigan State University, East 

Lansing, MI 

We have previously shown that GnRH, a peptide present in the terminal 

nerve, modulates the voltage-dependent Na + current and general 

odorant responses in salamanders. In this study, we used whole-cell 

patch clamp recordings to investigate the effects of GnRH on K + 

currents in isolated olfactory receptor neurons from tiger salamanders 

(Ambystoma tigrinum). First, we demonstrated that bath application of 

10 µM GnRH onto olfactory receptor neurons suppresses outward 

currents in 42% of cells tested. We are now determining which outward 

currents are affected by GnRH. Substituting Ba2+ for Ca2+ to block 

activation of Ca2+ -dependent currents, we found that application of 

GnRH decreases the magnitude of Ca2+ -independent outward currents 

by about 50% in 60% of the cells examined. We then blocked the 

transient K + current ('A current') by adding 5 mM 4-aminopyrine (4- 

AP) to the bath in addition to Ba2+ , and found that GnRH suppresses the 

magnitude of the delayed rectifier K + current in 39% of the cells tested. 

We are now investigating the effects, if any, of GnRH on the transient 

K + current and on the Ca2+ -dependent K + current. In addition to the 

suppressive effects described here, we have found that about 10% of the 

cells tested display an increase in the overall outward current during 

GnRH application. These results demonstrate that GnRH modulates 

voltage-activated K + currents. Overall, terminal nerve modulation may 

play an important role in peripheral olfactory signal transduction. This 

study was conducted in accordance with PHS guidelines, and supported 

by NSF (IBN 9982934) and NIH (DC05366). 

40 


PUTATIVE REPRODUCTIVE PHEROMONES IN THE ROUND 

GOBY, NEOGOBIUS MELANOSTOMUS: BIOSYNTHESIS 

AND OLFACTORY MUCOSAL RESPONSES. 

Arbuckle W. 1, Belanger A. 2, Scott A. 3, Li W. 4, Corkum L. 1, Yun S.S. 4, 

Yu K. 1, Zielinski B. 1 1Biological Sciences, University of Windsor, 

Windsor, Ontario, Canada; 2University of Windsor, Windsor, Ontario, 

Canada; 3The Center for Environment, Fisheries and Aquaculture 

Sciences, Weymouth, Dorset, United Kingdom; 4Fisheries and Wildlife, 

Michigan State University, East Lansing, MI 

Previous studies indicate that, in the round goby Neogobius 

melanostomus, the reproductively mature male releases a pheromone 

that attracts ripe females. These studies furthermore suggest that the 

pheromone may be a steroid (more specifically a 5 β reduced androgen) 

produced by specialized glandular tissue in the testes. In the present 

study, in vitro incubation of the testes converted [3H]-androstenedione 

into (in order of abundance): 5 β -androstan-3;α -ol-11,17-dione 

(11keto-etiocholanolone, 11K-ETIO); 11KETIO sulfate (11K-ETIO-s); 

11-ketotestosterone; 5 β -androstan-3 α-ol-17-one (etiocholanolone, 

ETIO); 11-;β hydroxy-androstenedione; ETIO sulfate and testosterone. 

11K-ETIO and 11K-ETIO-s appear to be novel compounds in teleost 

gonads. While olfactory potency of 11K-ETIO-s has not been tested, 

the response threshold concentration was 0.1 nanomolar for the 11K- 

ETIO and ETIO sulfate, when olfactory mucosal activity was measured 

by electro-olfactogram (EOG). The other compounds elicited olfactory 

mucosal responses at concentrations greater than 0.1 nanomolar. For 

11K-ETIO, ETIO sulfate, and 11-ketotestosterone; EOG response 

magnitudes in ripe females were significantly greater than in nonovulated 

females. In addition, the fact that the carbon A ring of 11K- 

ETIO and 11K-ETIO sulfate have a 5 β -configuration (already linked 

with olfactory sensitivity and behavior induction in two species of 

gobies) makes these likely candidates pheromones in the round goby. 

Supported by the Michigan Great Lakes Protection Fund, NSERC 

and the University of Windsor Faculty of Graduate Studies


THE RABBIT MAMMARY PHEROMONE ELICITS 

RESPONSES IN THE MAIN OLFACTORY EPITHELIUM OF 

NEWBORN RABBITS AND RATS. 

Jakob I. 1, Litaudon P. 2, Schaal B. 1, Sicard G. 2 1Centre des Sciences du 

Gout, CNRS, Dijon, France; 2Neurosciences et Systemes Sensoriel, 

Universite Lyon I, Lyon, France 

As previously described newborn rabbits rely for survival on a 

pheromone released from the doe´s nipples (Hudson & Distel, 1983). 

The pheromone inducing suckling behavior in rabbit pups has been 

identified in rabbit milk as a single compound, namely trans-2-methyl- 

2-butenal (2MB2), and acted behaviorally species specific failing to 

induce suckling behavior in rat pups (Schaal et al, 2003). Using an air 

dilution olfactometer we recorded electro-olfactograms (EOG) on 18 

different sites of the mucosa of the nasal septum and turbinates of 

newborn rabbits and rats from postnatal days 2 to 11. We tested 2MB2, 

3 structurally related odorants, 1 with similar odor quality , and 3 

unrelated general odorants. Most recording sites of the septal and 

turbinate mucosa of rabbit and rat were responsive to all 8 odorants. All 

stimuli elicited typical EOGs with a rapid rising phase and a slower 

decline. Amplitudes to a given stimulus at a given recording site varied 

from animal to animal and were not age dependent. Topographic 

pattern for maximum sensitivity of 2MB2 were different in all 

individuals. 2MB2 was the most potent stimulus only in 30% of the 

instances tested. All recording sites sensitive to 2MB2 responded also 

to several other test odorants. This indicates that the olfactory mucosa 

of newborn rabbit and rat exhibited neither regions of specific 

selectivity nor a general increase in sensitivity to 2MB2. Supported by a 

grant from Ministere de la Recherche, ACI “Neurosciences Integratives 

et Computationnelles” 

159 Poster [ ] Environment and Human Olfaction 

CHILDREN´S PREFERENCES FOR TOBACCO ODOR: 

EFFECTS OF MATERNAL SMOKING AND MOOD STATES 

Forestell C.A. 1, Maggi L. 1, Mennella J.A. 1 1Monell Chemical Senses 


Ongoing research in our laboratory focuses on children´s hedonic 

judgments of and preferences for odors as a function of the context of 

early experience. Age-appropriate, game-like tasks that were fun for 

children and minimized impact of language development were used to 

examine responses of 3- to 9-year-old children (N=296) and their 

mothers to a variety of odors ranging in hedonic valence and 

familiarity, one of which was tobacco smoke. Parental smoking, as well 

as the mood state of the parent, as determined by standard tests (e.g., 

Beck Depression Inventory), influenced children´s preference for 

tobacco odors. The data revealed that women who smoked liked the 

tobacco odor significantly more than non-smoking women. Likewise, 

children whose parents smoked were significantly more likely to prefer 

the odor of cigarette relative to neutral odors when compared to 

children of non-smokers. This preference for the tobacco odor was 

significantly less pronounced in children of smoking mothers who were 

depressed when compared to children of non-depressed smoking 

mothers. Depressed smoking mothers also scored significantly higher 

on the POMS Tension, Fatigue, Anger and Confusion and lower on the 

vigor scales when compared to non-depressed smoking mothers. These 

findings suggest that children's preferences for the odor of tobacco 

smoke are related to the emotional context in which their mothers 

experience tobacco. This research was supported by Pennsylvania 

Research Formula Fund and NIH Grants AA09523. 

41 


ANDROSTADIENONE EXPOSURE MODULATES MOOD 

RATINGS BUT NOT BEHAVIOR IN WOMEN 

Lundstrom J.N. 1, Olsson M.J. 1 1Psychology, Uppsala University, 

Uppsala, Sweden 

Exposure to the endogenous steroid androstadienone has repeatedly 

been shown to modulate women´s feeling of being focused in a positive 

direction (Lundström et al., 2003). The aim of the current study was to 

investigate whether exposure to a subthreshold concentration of 

androstadienone would also facilitate behavioral performance in an 

attention task. Thirty-seven women participated in a double-blind 

within-group experiment where they performed a 20-minute tracking 

task measuring sustained attention. Either a male or a female ran the 

experiment. The experimental substance contained 250µM 

androstadienone. Both the experimental and control substances were 

masked by eugenol in order not to be perceptually discriminable. 

Effects on mood variables as well as attraction ratings of male faces 

were measured. Exposure to androstadienone modulated participant´s 

mood in that they felt more focused, social, happy, and less irritated. 

Interactions between test substance and sex of experimenter indicated 

that the presence of a male experimenter enhanced some of the effects 

in a positive direction. However, no effects on attention performance or 

attraction ratings were found. 

Support: The Swedish Research Council (HSFR: F0868) 


SMELLING A PARTNER'S CLOTHING DURING PERIODS OF 

SEPARATION: PREVALENCE AND FUNCTION 

Mcburney D.H. 1, Shoup M.L. 1, Streeter S.A. 1 1Psychology, University 

of Pittsburgh, Pittsburgh, PA 

Scattered reports in both the scientific and popular literature, as well 

as personal anecdotes suggest that it is not uncommon for persons to 

deliberately smell their sexual partner´s clothing, especially when 

separated. To our knowledge there has been no documentation of the 

frequency of this behavior. We asked undergraduate men and women 

who were, or had ever been, in a committed heterosexual relationship if 

they had ever deliberately smelled their partner´s clothing, or had slept 

with an article of their partner´s clothing, during periods of separation. 

A large majority of women had done one of these behaviors at least 

once; men reported doing it much less. We discuss possible functions 

of this behavior. It is possible individuals may be evaluating their 

partner´s MHC or other signals of health provided by odor, but that 

would not explain why the behavior occurs in the partner´s absence. 

Attractiveness of a partner´s odor may derive from its value in signaling 

the fitness benefits provided by a mate´s presence. The sex difference 

may reflect the fact that women especially benefit from the protection 

provided by a mate, or the greater importance women place on their 

partner´s odor (Herz & Cahill, 1997), or the greater choosiness of 

women in mate selection (Buss & Schmitt, 1993).


HUMAN OLFACTORY DETECTIONS OF SOCIAL AND NON- 

SOCIAL CHEMOSIGNALS 

Miller L. 1, Nomura M. 1, Umeh Y. 1, Villarreal R. 1, Chen D. 2 

1Psychology Department, Rice University, Houston, TX; 2Rice 

University, Houston, TX 

Olfaction is important for the survival of many animals and used for 

detection of a wide range of social and nonsocial information. Research 

in animals (Petrulis, et al., 1999) suggests that the mechanisms involved 

in processing smells serving different functions (e.g., food vs. 

reproduction) may be different. Previous research shows that humans 

can recognize individuals, distinguish between emotional states (Chen 

& Haviland-Jones, 2000; Chen & McClintock, in preparation), and 

make fine discriminations between various nonsocial smells, although 

few has examined olfactory sensitivities to different types of social and 

nonsocial smells within the same study. In this study, we investigate 

and compare human olfactory sensitivities to a variety of social and 

nonsocial chemosignals. Thirty-two college-aged adults were asked to 

identify themselves, their roommate, and to distinguish between 

different emotional states based on the smell of sweat. Their 

sensitivities to nonsocial smells were also assessed using established 

clinical tests (threshold and odor identification tests). Over three-fourths 

of the subjects identified themselves in a well-controlled three-itemforced-choice 

task (chance = 33%, p


PERITHRESHOLD NOT SUPRATHRESHOLD EXPOSURE 

INCREASES SENSITIVITY TO ODORS 

Diamond J. 1, Dalton P. 1, Breslin P.A. 1 1Monell Chemical Senses 


Repeated threshold test exposures to perithreshold odorants can lead 

to dramatic sensitivity increases among young women, (Dalton, 

Doolittle & Breslin, 2002), even when the target odorant is 

superimposed on a suprathreshold `background´ odorant (Dalton, 

Diamond & Breslin, 2003). To evaluate whether this phenomenon is 

concentration-dependent such that perithreshold stimulation is required 

to induce sensitization, 9 subjects (5 females, 18-24) were exposed to 

suprathreshold concentrations of benzaldehyde or citralva in the process 

of determining Weber fractions. After multiple sessions, absolute odor 

detection thresholds were measured for experimental and control odors. 

In contrast to prior studies, we found no difference in sensitivity 

changes between males and females: sensitivity to both control and 

experimental odors increased up to 1 order of magnitude for both 

groups. The same subjects were later exposed to perithreshold 

concentrations of one of the experimental odors over ten sessions. 

Under these conditions, females increased sensitivity by almost three 

orders of magnitude, whereas males increased sensitivity by only 

slightly more than one. This suggests that attention to suprathreshold 

stimulation was insufficient to elicit sensitization and that perithreshold 

stimuli may be required. 

Supported by NIH RO1 DC 03704 & RO1 DC 02995 


ODOR PERCEPTION AND JUDGED PROBABILITIES OF 

HEALTH RISK 

Dalton P. 1, Maute C. 1, Naqvi F. 1 1Monell Chemical Senses Center, 


The purpose of the present study was to determine how intuitive 

notions about the significance of odor from a chemical source combine 

with rational, scientific information to form risk judgments in 

individuals. Subjects were given information pertaining to an 

imaginary odor, including the following benchmarks: the concentration 

(in parts per million) at which the odor can be detected, the 

concentration at which the odor is considered harmless, and the 

concentration at which the odor is considered harmful. In addition to 

this information, three samples of 1-butanol at varying concentrations 

were provided to correspond to these benchmarks of the imaginary 

odor. The order of the benchmarks was different for each of three 

groups tested. Armed with this information, subjects were asked to rate 

the level of risk associated with exposure to several concentrations of 

the imaginary odor that fell above and below the benchmarks provided. 

Half of the subjects were given a tight range of concentrations to rate 

while the other half were given a wider range of concentrations. 

Results show that participants consistently perceived the chemical as 

being more harmful after it exceeded the level of odor detection than 

when it was below the level of detection, regardless of whether odor 

perception occurred above or below levels associated with toxicity. 

Supported by NIH RO1 DC03704-06 

43 

168 Poster [ ] Trigeminal Chemoreceptors 

P2X-RECEPTOR EXPRESSION AND THEIR CONTRIBUTION 

TO CHEMOSENSATION IN TRIGEMINAL NEURONS 

Spehr J. 1, Spehr M. 1, Hatt H. 1, Wetzel C. 1 1Zellphysiologie, Ruhr- 

Universität Bochum, Germany, Bochum, Germany 

The facial innervation pattern of trigeminal nerve fibres comprises 

the innervation of the nasal epithelium, where free trigeminal nerve 

endings contribute to detection and discrimination of chemical stimuli 

including odorants. The signal transduction mechanisms in sensory 

nerve endings underlying perception of chemical stimuli remain widely 

uncovered. Here, we characterized trigeminal ATP-activated P2Xreceptors 

in cultured rat trigeminal neurons and investigated their role 

in chemoperception. We identified a new subpopulation of neurons 

lacking typical nociceptive characteristics and expressing homomeric 

P2X2-receptors. Using a certain group of chemicals known as 

trigeminal stimuli we found no direct activation of trigeminal neurons, 

but a modulation of P2X2-receptor mediated currents. In contrast, 

P2X3-receptor mediated currents of nociceptive trigeminal neurons 

remained unaffected by the tested chemicals. Therefore, we assume a 

functional role of the newly identified subpopulation in chemodetection 

of certain trigeminal stimuli. 


SINGLE NUCLEOTIDE POLYMORPHISMS (SNPS) IN THE 

CAPSAICIN RECEPTOR: RELATIONSHIP TO CHEMO- 

SENSORY PERFORMANCE IN A PILOT SAMPLE 

Tarun A. 1, Shusterman D.J. 1 1Medicine, University of California, San 

Francisco, Richmond, CA 

The capsaicin or vanilloid (VR1 / TRPV1) receptor responds to 

multiple noxious stimuli, including H + , heat, and capsaicin and its 

analogs. We recently observed marked inter-individual variation in 

subjective rating of capsaicin solution applied topically to the nasal 

mucosa in human subjects, and hypothesized that sequence variations in 

the TRPV1 gene could be responsible for this phenomenon. To test this 

hypothesis, we sampled genomic DNA from ten subjects (4 females, 6 

males; age range 24-56 years), all of whom had undergone trigeminal 

threshold testing with CO 2 (an acid producer) and six of whom had 

given suprathreshold irritation ratings to nasal capsaicin challenge. We 

sequenced five coding regions with known single nucleotide 

polymorphisms (SNPs) in the TRPV1 gene in each of the genomic 

DNA samples. Three of these SNPs resulted in a non-synonymous 

change in amino acid sequence of TRPV1. We found polymorphism in 

two of these non-synonymous SNPs. However neither of these 

polymorphisms correlated with either capsaicin suprathreshold rating or 

CO 2 threshold performance of the ten subjects. The only obvious 

chemosensory correlation was heterozygosity in one SNP resulting in a 

synonymous change in TRPV1 sequence in one subject with unusually 

low ratings of capsaicin irritancy. In this small pilot sample we 

demonstrated the feasibility of comparing chemosensory performance 

with sequence variation in the TRPV1 receptor gene. However, our 

results suggest that none of the five SNPs initially examined predicts 

inter-individual differences in capsaicin and CO 2 perception.


CAPSAICIN SELF-SENSITIZATION IN CULTURED 

TRIGEMINAL NEURONS 

Bryant B. 1 1Monell Chemical Senses Center, Philadelphia, PA 

Sensitization of peripheral somatosensory neurons is one means by 

the amplification of the system can be modulated in certain cases of 

tissue damage and pathology. It is well known, for instance, that 

bradykinin (an endogenous algogen released on tissue injury) sensitizes 

somatosensory neurons to heat and capsaicin (CAP). When CAP is 

periodically applied to the oral mucosa at short intervals, typically 1 

min between stimuli, the reported irritation increased over time and has 

been termed sensitization (Green, 1991). Studies in which cultured 

trigeminal or dorsal root ganglion neurons have been exposed to 

repeated stimulation with CAP have only reported desensitization of 

subsequent responses to CAP stimulation. Because of this, it has been 

most tempting to attribute the observed increases in the intensity of 

sensory irritation to either a slow increase in the peripheral tissue 

concentration of CAP or to sensitization of central processes. To 

examine the peripheral basis of CAP self-sensitization, intracellular 

calcium responses of fura2-loaded rat trigeminal neurons were 

measured. Tested at concentrations lower (50nM - 1 uM) than 

previously tested (1-10 uM), CAP induced self-sensitization in a 

portion of neurons. At 1uM, repeated stimulation with CAP only 

induced the same amplitude or decremented responses. Between 50 and 

300 nM CAP, up to 46.2% of CAP-sensitive neurons exhibited 

sensitization. This suggests that a balance between sensitizing and 

desensitizing processes occurs in trigeminal neurons with the 

desensitizing processes having a higher threshold. Although narrow in 

concentration range, this demonstrates that peripheral self-sensitization 

by CAP does take place. 


THE EFFECT OF VR1 BLOCKERS ON PERIPHERAL 

TRIGEMINAL NERVE RESPONSES TO IRRITANTS 

Allgood S. 1, Silver W.L. 1 1Biology, Wake Forest University, Winston- 

Salem, NC 

The vanilloid receptor (VR1, aka TRPV1), present on trigeminal 

nerve fibers, is a non-selective cation channel with high permeability 

for divalent cations. VR1 responds to heat, acids and capsaicin but its 

specific role in trigeminal stimulation by irritants has not been well 

studied. Our study seeks to further investigate the role of VR1 in 

peripheral trigeminal nerve responses. Neural recordings were obtained 

from the ethmoid nerves of adult rats in response to irritants delivered 

in solution to the nasal cavity. The ethmoid nerve responded to 

capsaicin, propionic acid, cyclohexanone and nicotine. When these 

compounds were presented with ruthenium red, an inhibitor of Ca2+ transport through membrane channels, there was a decreased response 

to capsaicin, propionic acid and cyclohexanone, but no change in the 

response to nicotine. When these compounds were presented with 

capsazepine, a competitive VR1 inhibitor, there was a decreased 

response to capsaicin and cyclohexanone, but no change in the response 

to nicotine and propionic acid. These data indicate that while capsaicin, 

cyclohexanone and propionic acid may at least partially exert their 

effect through VR1, nicotine does not. Additionally, these data show 

that while both ruthenium red and capsazepine work to block VR1 

receptors, they do so in different ways, as exhibited by their effect on 

the propionic acid response. Future work will look at additional 

compounds and receptor blockers to better understand the mechanisms 

of trigeminal nerve nociception. 

44 


PERSISTENCE OF NASAL SOLITARY CHEMORECEPTOR 

CELLS AFTER NEONATAL CAPSAICIN TREATMENT 

Finger T.E. 1, Gulbransen B. 1, Böttger B. 1, Alimohammadi H. 2, Silver 

W.L. 2 1Rocky Mountain Taste & Smell Ctr., University of Colorado 

Health Sciences Center, Denver, CO; 2Biology, Wake Forest 

University, Winston-Salem, NC 

Our recent studies (Finger et al. PNAS 2003) show that nasal 

trigeminal chemosensitivity in mice and rats is mediated in part by 

solitary chemosensory cells (SCCs) distributed throughout much of the 

nasal respiratory epithelium. These SCCs express gustducin and T2R 

(bitter) taste receptors, and synapse onto peptidergic (substance 

P/CGRP) fibers of the trigeminal nerve that densely innervate the 

receptor cells. Administration of capsaicin to neonatal rat pups (0.1ml 

of a 1% capsaicin solution, 50 mg/kg) destroys the peptidergic 

trigeminal ganglion cells and effectively eliminates the trigeminal 

neural response to most irritants. These experiments were designed to 

test whether capsaicin-mediated elimination of trigeminal peptidergic 

innervation reduced or eliminated the nasal SCCs, i.e. whether nasal 

SCCs are dependent on innervation. Two-4 months following neonatal 

injection of capsaicin, rats were anesthetized and prepared for 

electrophysiology. In 3 of 3 desensitized animals, the ethmoid nerve 

showed no responses to cycloheximide solution applied to the nasal 

mucosa – a solution that evokes robust activity in normal animals. 

Following recordings, these and other desensitized rats were perfused 

with 4% paraformaldehyde and prepared for immunocytochemistry. 

Despite nearly total elimination of CGRP-immunoreactive nerve fibers, 

the gustducin-expressing nasal SCCs remained. Sparse non-peptidergic 

innervation of the epithelium remained (as assessed with PGP antisera) 

but these remaining nerve fibers did not form close, embracing contacts 

with the SCCs. 

Supported by NIDCD Grant DC0060770. 


PATTERNS OF VARIATION IN THE BEHAVIORAL 

RESPONSES OF RATS TO IRRITANTS AFTER NEONATAL 

CAPSAICIN TREATMENT 

Alimohammadi H. 1, Silver W.L. 1 1Biology, Wake Forest University, 

Winston-Salem, NC 

Administration of capsaicin to neonatal rat pups has been shown to 

produce adults with decreased trigeminal sensitivity to many irritants. 

This observed loss in chemosensitivity presumably occurs through the 

elimination of the vanilloid receptor-expressive cell population of the 

trigeminal ganglion, and it was hypothesized that the degree of 

desensitization in individual adults would vary depending on the 

efficacy of the initial capsaicin treatment. To test this hypothesis, a 

behavioral screen was developed to examine inter-animal variability in 

aversion responses to irritants. Adult rats injected with either capsaicin 

or a control solution as neonates were presented with a series of eight 

irritating/non-irritating chemical stimuli. Each rat´s response within the 

first few seconds of encounter with the stimulus source was then scored 

using a scale to measure aversive and/or favorable responses. Neonatal 

capsaicin treatment was found to result in varying degrees and differing 

patterns of desensitization to the five irritants tested. While most of the 

capsaicin-injected rats displayed diminished aversion reactions when 

compared to control animals, a few (3 of 13) were found to be more 

sensitive than the least sensitive control animal. Among the most 

desensitized animals, sensitivity to acetic acid remained intact whereas 

sensitivity to nicotine, cyclohexanone, amyl acetate, and ethanol were 

diminished. Capsaicin treatment had no effect on the behavioral 

response to non-irritating stimuli. These findings show that neonatal 

administration of capsaicin does not guarantee a desensitized-adult 

state, and may result in varying degrees of desensitization.


TOPOGRAPHICAL DIFFERENCES IN THE SENSITIVITY OF 

THE INTRANASAL TRIGEMINAL SYSTEM 

Frasnelli J. 1, Heilmann S. 1, Hänel T. 1, Hummel T. 1 1University of 

Dresden Medical School, Dresden, Germany 

Preliminary data indicate that the nasal mucosa shows a differential 

responsiveness to trigeminal stimuli depending on the site of 

stimulation. Aim of the present study was the comparison of the 

sensitivity of two different areas of the respiratory epithelium to 

mechanical (air puffs) and chemosensory (gaseous CO2) stimuli. 

Specifically, stimuli were applied to the anterior portion of the nasal 

cavity and to the pharyngeal area. Responses were quantified using 

psychophysical (intensity) and electrophysiological (event related 

potentials - ERPs) techniques. For all measured parameters, a 

significant interaction between “location” * “stimulus” emerged, 

indicating that (i) CO2 evoked ERP of higher amplitude and higher 

intensity ratings when applied to the anterior portion of the nasal cavity 

compared to pharyngeal stimulation, and (ii) mechanical stimuli elicited 

larger responses when presented to the pharynx than to the anterior 

nasal cavity. These findings suggest that the nasal mucosa does not 

exhibit a homogenously distributed sensitivity, but that, in addition to 

the olfactory mucosa, there are areas with specific sensory function. 

These topographical differences in intranasal sensitivity may play a role 

in terms of differences between the ortho- and retronasal perception of 

odors. 


VIRAL TRACING OF MURINE TRIGEMINAL NEURONS 

INNERVATING THE NASAL CAVITY 

Damann N. 1, Klupp B. 2, Mettenleiter T.C. 2, Hatt H. 1, Wetzel C. 1 1Cell 

physiology, Ruhr-University, Bochum, Germany; 2Friedrich-Loeffler- 

Institute, Bundesforschungsanstalt für Viruskrankheiten der Tiere, Insel 

Riems, Germany 

The trigeminal nerve is the major mediator of sensations from the 

mammalian head and comprises neurons that transduce mechanical, 

thermal and chemical stimuli. Thereby single neurons mediate sensory 

input from selective areas of the head (meninges, cornea and 

conjunctiva of the eyes, facial skin, mucous membranes of the oral and 

nasal cavities). Differential physiological features of peripheral neurons 

depending on their function and area of innervation remain largely 

unclear. Viral tracing was performed to identify trigeminal neurons that 

mediate information from the murine nasal cavity. After application of 

high titered Pseudorabies virus (PrV) into the nose, markerprotein and 

immunhistochemistry based investigations were carried out. Paraffin 

embedded sections and whole mount preparations were used to describe 

viral spread. Histochemical investigations revealed an ipsilateral spread 

via the ophthalmic division of the trigeminal nerve to the gasserian 

ganglion (GG). Infected GFP labeled ganglion neurons could also be 

identified after dissociation and plating allowing activity measurement 

of individual identified neurons in primary cell culture. PrV constitutes 

a powerful tool to perform rapid tracing of the murine trigeminal 

system and affords the possibility to selectively label neurons 

innervating the nose. Electrophysiological and calcium imaging based 

characterization of these neurons concerning their specificity for 

selected chemical compounds shall be performed in future research. 

45 


GENDER DIFFERENCES AND NASAL INTEGRATION 

STUDIES PERFORMED USING AN OCULAR EXPOSURE 

DEVICE FOR DETECTION OF IRRITATION THRESHOLDS: 

THE T.I.D.E. SYSTEM 

Opiekun R.E. 1, Mcdermott R. 1, Dalton P. 1 1Monell Chemical Senses 


Ocular irritation from low-level volatile chemicals is one of the most 

common complaints in occupational and residential environments. In 

contrast with techniques available for nasal irritation assessment, 

however, there are few standardized methods available for measuring 

ocular irritation thresholds. Based on the lateralization technique 

originally developed for nasal irritation thresholds, we have developed 

an instrument that can deliver controlled concentrations of a chemical 

vapor to one eye and a blank stimulus to the other without producing 

mechanical somatosensory stimulation that might alter ocular 

thresholds for chemicals. Initial results suggest that this system can be 

very useful for objective measurement of ocular irritation, that 

simultaneous nasal stimulation affects ocular thresholds and that 

females have a lower ocular threshold upon integration than males. 

Results also indicate that while there is a wide variation of ocular 

irritation thresholds among individuals, vapor concentrations required 

to initiate conjunctival irritation can be substantially lower than those 

encountered in occupational settings. 


LATERALIZATION OF CHEMOSENSORY STIMULI: 

EFFECTS OF OLFACTORY FUNCTION, AGE AND GENDER 

ON TRIGEMINALLY MEDIATED SENSATIONS 

Reden J. 1, Futschik T. 1, Frasnelli J. 2, Huettenbrink K. 2, Hummel T. 3 

1Department of Otorhinolaryngology, University of Dresden Medical 

School, Dresden, Germany; 2Otorhinolaryngology, University of 

Dresden Medical School, Dresden, Germany; 3University of Dresden 

Medical School, Dresden, Germany 

The present investigation aimed to compare trigeminal nasal function 

of anosmic and hyposmic patients to healthy controls. Further, we 

aimed to study effects of age and gender on trigeminally mediated 

sensations following intranasal chemosensory stimulation. Participants 

were 35 patients with olfactory disfunction (n=13: functional anosmia; 

n= 22: hyposmia; age 28-69 years). Their results were compared with 

17 normosmic subjects (age 28-82 years). Olfactory function was 

assessed using the “Sniffin´ Sticks” test kit (butanol odor threshold, 

odor discrimination, odor identification). The subjects´ ability to 

lateralize odors was investigated for benzaldehyde and eucalyptol. 

Patients with olfactory dysfunction had lower scores in the 

lateralization task than controls (P

178 Poster [ ] Functional Organization of the Gustatory 

System 

ION SUBSTITUTION AFFECTS THE LINGUAL SURFACE 

POTENTIAL (LSP) IN HUMANS 

Feldman G. 1, Heck G. 2, Mogyorosi A. 1 1Medicine, Virginia 

Commonwealth University, Richmond, VA; 2Physiology, Virginia 

Commonwealth University, Richmond, VA 

We have demonstrated in humans that Na + evokes a LSP and that 

amiloride inhibits a portion of the Na + -evoked LSP in some but not all 

subjects (J. Neurophysiol. 90: 2060, 2003). To further characterize 

electrophysiologic aspects of the human tongue we examined whether 

ion substitutes influence the LSP. Initial studies employed K + and Li + , 

because Li + transits Na + -selective pathways, e.g. ENaC, while K + does 

not readily transit such pathways. The LSP response to K + and Li + 

depended on whether the individual´s Na + -evoked LSP was inhibited by 

amiloride. In subjects who manifested amiloride sensitivity, K + 

substitution reduced the LSP, while Li + ´s effect was similar to that of 

Na + . In these subjects, after addition of amiloride to solutions, the Na + - 

and Li + -evoked LSPs were reduced and were similar to that of K + . In 

subjects who had no amiloride sensitivity, the effect of K + on the LSP 

was similar to those of Na + and Li + . In other studies gluconate and 

sulfate replaced Cl – . While the substitute anions increased the Na + - 

evoked LSP, the sulfate effect was approximately 3 fold greater than 

that of gluconate. The effects of the anion substitutes were not 

influenced by amiloride or the subject´s sensitivity to amiloride. These 

data complement our previous observation that some but not all 

individuals manifest amiloride sensitivity of their Na + -evoked LSP. 

These data also indicate that the amiloride sensitive Na + pathway 

allows Li + to transit, but excludes K + , consistent with the presence of 

ENaC in a subset of humans. Anions also influence the Na + -evoked 

LSP, but they do so independently of ENaC. 

46 


System 

EXPRESSION OF DELAYED RECTIFYING K CHANNELS IN 

TASTE CELLS OF OBESITY-PRONE AND –RESISTANT 

RATS. 

Hansen D.R. 1, Gilbertson T.A. 1 1Biology & Center for Integrated 

BioSystems, Utah State University, Logan, UT 

Direct fatty acid-mediated inhibition of delayed rectifying potassium 

(DRK) channels, specifically those in the Shaker subfamily (Kv1), has 

been proposed as a taste transduction mechanism for dietary fat. Our 

previous work demonstrated that fungiform TRCs responded only to 

cis-polyunsaturated fatty acids (PUFAs), while those found in the 

foliate and vallate papillae, responded to both PUFAs and a subset of 

monounsaturated fatty acids. In addition we demonstrated that TRC 

sensitivity to PUFAs was inversely correlated with dietary fat 

preference. Patch clamp recording has shown that TRCs in Osborne- 

Mendel (OM) rats, which show a marked preference for dietary fat and 

become obese when placed on a high fat diet, are much less sensitive to 

PUFAs than are TRCs in S5B/Pl (S5B) rats that tend to avoid fat and 

remain lean even on a high fat diet. Our hypothesis is that TRCs in S5B 

rats express a greater ratio of fatty acid-sensitive to fatty acidinsensitive 

DRK channels than do those in OM rats. To determine if 

this difference in PUFA responsiveness is correlated with expression 

levels of DRK channels, we used real-time quantitative PCR to measure 

expression levels of DRK channels in taste buds from OM and S5B 

rats. Consistent with DRK current densities, which are twice as great in 

OM rats than in S5B rats, TRCs from OM rats exhibit greater 

expression of DRK channels. Specifically, the Kv2 (Shab) and Kv3 

(Shaw) DRK channel families, which may represent the PUFAinsensitive 

DRK channels, are much more highly expressed in OM rats 

than in S5B rats consistent with our hypothesis. Supported by NIH 

DK59611 (TAG). 


System 

THE PORE-FORMING ANTIBIOTIC NYSTATIN INHIBITS 

TASTE CELL K CURRENTS IN PERFORATED PATCH 

RECORDINGS. 

Klein J.T. 1, Guenter J. 1, Rosenthal A. 1, Gilbertson T.A. 1 1Biology & 

Center for Integrated BioSystems, Utah State University, Logan, UT 

Nystatin and amphotericin B, pore-forming antibiotics commonly 

used in perforated patch clamp recording, have been shown to inhibit 

and increase the rate of inactivation of the delayed rectifying K channel 

Kv1.3 when applied to the intracellular face of the membrane (Hahn et 

al. Neuropharmacology 35: 895, 1996). Since it is not known whether 

these antibiotics can gain access to the intracellular face and affect K 

currents in the perforated patch configuration, we investigated this 

possibility in taste receptor cells (TRCs), which we have shown by RT- 

PCR and immunocytochemistry to express Kv1.3 as well as other 

delayed rectifying K channels. We found that nystatin, but not 

amphotericin, caused roughly a 40% inhibition of delayed rectifying K 

currents in TRCs at 20 min. and increased the rate of inactivation 

several fold. This difference between nystatin and amphotericin may be 

due to the fact that the IC 50 of amphotericin´s effects on Kv1.3 is ~18 

times higher than that of nystatin, while the concentrations of 

amphotericin we found necessary to gain good electrical access to the 

TRCs was only 2-3 times higher than the concentrations of nystatin. 

Thus, one should exert caution when using pore-forming antibiotics in 

perforated patch recordings because of possible effects on ionic 

currents. Supported by DC02507, DC00347, DC00353 and UAES 630 

(TAG).


System 

THE CELLULAR AND MOLECULAR BASIS FOR WATER 

TASTE IN MICE. 

Spray K.J. 1, Baquero A. 1, Gilbertson T.A. 1 1Biology & Center for 

Integrated BioSystems, Utah State University, Logan, UT 

Recent studies have begun characterizing water (hypoosmotic 

stimuli) responses in the peripheral gustatory system in rat. Increases in 

activation were associated with rapid and reversible changes in cell 

volume. Such rapid changes in cell volume may be due to aquaporin 

channels (AQP) previously identified in taste receptor cells (TRC). We 

have begun examining this response in two inbred mice strains 

(C57/6ByJ & 129X/SvJ) using whole cell patch clamp recording. 

Approximately half of the fungiform TRCs in each strain responded to 

a moderately hypoosmotic solution (255 mOsm) with reversible 

increases in conductance, presumably due to activation of a volumesensitive 

Cl channel. Immunocytochemistry showed apical expression 

of AQP5 in isolated fungiform TRCs in both strains. We have also 

examined how these mice respond behaviorally to changes in solution 

osmolarity using mannitol (believed to be tasteless) to alter tonicity. 24h 

3-bottle intake tests assessed preferences for several concentrations of 

mannitol (55 mM-330 mM) to distilled water. As concentration 

(osmolarity) increased, we found decreased mannitol preference. There 

were also significant strain differences at lower concentrations. 

Preference scores for mannitol were lower for the B6 than 129 mice. 

Therefore, mice respond to changes in osmolarity both behaviorally and 

at the cellular level. In addition, expression of water channels, 

particularly the apically expressed AQP5, may play an important role in 

the initial transduction events. Current studies are addressing the link 

between AQP expression and water responsiveness in mice. Supported 

by NIH DC02507 (TAG). 


System 

MONITORING T1R TASTE RECEPTOR DIMERIZATION 

Ji Q. 1, Snyder L. 2, Benard L. 1, Max M. 2, Margolskee R. 1 1Department of 

Physiology & Biophysics, Howard hughes medical institute, Mount 

Sinai School of Medicine, New York, NY; 2Department of Physiology & 

Biophysics, Mount Sinai School of Medicine, New York, NY 

T1Rs are taste cell-expressed type 3 G-protein-coupled receptors 

(GPCRs). Dimerization of T1R receptors has been inferred, but not 

actually shown. We have used BRET (Bioluminescence Resonance 

Energy Transfer) assay to demonstrate T1R receptor dimerization. 

BRET2 assay is based on energy transfer between fusion proteins 

containing Renilla luciferase (Rluc) and Green Fluorescent Protein 

(GFP). 

Human T1R1 (hT1R1), hT1R2 and hT1R3 coding regions were 

subcloned into Rluc and GFP vectors. HEK-293T cells were cotransfected 

with all pairs of hT1R-Rluc and hT1R-GFP plasmids. 

Significant BRET signals were observed in cells expressing hT1R1 & 

T1R3 pairs, hT1R2 & hT1R3 pairs, but not hT1R1 & hT1R2 pairs. 

Saturation curves were constructed for each dimer pair. BRET signals 

were largely independent of receptor density indicating that they came 

from dimerization and not random collision events. BRET competition 

assays with untagged hT1R3 reduced the dimer BRET signal, 

confirming the specificity of the interactions. We generated multiple 

hT1R3 mutants to investigate the effects of disulfide bonds on dimer 

formation and ligand binding. 

47 


System 

EXPRESSION OF RGS IN TASTE BUD CELLS 

Wang H. 1, Max M. 2, Margolskee R. 3, Brand J. 1, Huang L. 1 1Monell 

Chemical Senses Center, Philadelphia, PA; 2Physiology and 

Biophysics, Mount Sinai School of Medicine, New York, NY; 3Howard 

Hughes Medical Institute, The Mount Sinai School Of Medicine, New 

York, NY 

Bitter, sweet and umami taste stimuli are detected by G-protein 

coupled receptors. The activation of these receptors in turn stimulates 

heterotrimeric G proteins, and triggers signal transduction cascades, 

eventually leading to a change in cell membrane potential and the 

release of neurotransmitters onto afferent axons. Recently, we and 

others have isolated several key taste transduction molecules. However, 

the mechanisms underlying the termination and desensitization of taste 

responses remain to be determined. To identify proteins that are 

involved in taste signal processing and peripheral coding, we isolated 

individual taste receptor cells, amplified single cell transcriptomes and 

constructed single taste cell cDNA libraries. By subtractively screening 

these libraries, we isolated a number of genes that are selectively 

expressed in taste cells. Among them is a regulator of G protein 

signaling (RGS) protein, which presumably serves as a negative 

regulator of heterotrimeric G-protein mediated signaling pathways by 

stimulating GTPase activity of the α subunits. In situ hybridization 

showed that this RGS is expressed in a subset of taste receptor cells. 

Further analysis of its interaction with taste signaling molecules in these 

taste cells could provide novel insights into our understanding of taste 

response processing and termination at the taste end organs. This work 

is supported by NIH grants DC05154(LH), DC03155(RFM) and 

MHS7241(MM), and a grant from VA(JGB). 


System 

DO TASTE CELLS THAT UTILIZE THE PLC SIGNALING 

PATHWAY ALSO EXPRESS VOLTAGE-GATED CALCIUM 

CHANNELS? 

Medler K. 1, Clapp T. 2, Sue K. 2 1Biomedical Sciences, Anatomy and 

Neurobiology Section, Colorado State University, Fort Collins, CO; 

2Biomedical Sciences, Colorado State University, Fort Collins, CO 

It has been well established that bitter, sweet, and umami taste 

stimuli are coupled to G proteins that activate the PLC signaling 

pathway (Zhang et al., Cell 2003). This pathway increases intracellular 

Ca 2+ via release from intracellular stores and store operated influx 

(Ogura et al., J. Neurophys. 2002). Recently, we showed that a 

subpopulation of these cells, the bitter-responsive, gustducin-expressing 

cells, lacks voltage-gated Ca 2+ channels (Medler et al., J. Neurosci., 

2003). However, it is not known if lack of voltage-gated Ca 2+ channels 

is a characteristic of all taste cells that use this pathway. In this study 

we used Ca 2+ imaging to determine if any PLC-responsive cells respond 

to depolarization with an increase in intracellular Ca 2+ . We found that 

cells that respond to a PLC activator rarely show increases in 

intracellular Ca 2+ when depolarized with KCl (55mM). In the cells that 

did respond to both, the response to the PLC activator was not robust. 

These data suggest either some overlap between excitable cells and the 

PLCβ2 signaling pathway or the presence of multiple PLC isoforms in 

taste cells. Further work is needed to clarify these results. Supported by 

DC00766 and DC 006021 to SCK.


System 

TASTE RESPONSE AND MOLECULAR EXPRESSION OF 

RECEPTOR CELLS OF THE MOUSE FUNGIFORM PAPILLAE 

Yoshida R. 1, Sanematsu K. 1, Ninomiya Y. 1 1Kyushu University, 

Fukuoka, Japan 

In taste bud cells, expression of various molecules concerned in taste 

reception was detected by various molecular biological techniques. 

Here, we investigated taste responses of receptor cells showing action 

potentials and mRNA expression of taste related genes in these cells at 

the same time. Using loose patch technique, we recorded increases in 

firing frequency from taste bud cells tested for taste stimuli (NaCl, 

Saccharin, HCl, Quinine HCl). Two types of NaCl responding cells 

exist: one is amiloride-sensitive and the other amiloride-insensitive. In 

some cells, responses to MSG were enhanced when MSG was mixed 

with IMP. Responses to sweet substances in some receptor cells were 

suppressed by apical treatment of gurmarin and recovered after apical 

application of β-cyclodextrin. Of 68 cells responding to taste stimuli, 40 

(59%) responded to one, 24 (35%) to two, and 4 (6%) to three of four 

taste stimuli. The entropy value presenting the breadth of 

responsiveness was 0.213 ± 0.252, which was close to that for the nerve 

fibers. These results suggest that taste cells generating action potentials 

have response characteristics to taste stimuli that are comparable to 

those for nerve fibers. After recording of taste response, single receptor 

cell was withdrawn from a taste bud and checked mRNA expression of 

taste related genes such as T1R3 by RT-PCR method. Our preliminary 

data indicate that a taste cell responding to sweet stimuli expressed 

T1R3 and gustducin mRNA. Thus, this technique might be useful to 

examine molecular expression in receptor cells responding to taste 

stimuli. 


System 

THE A BLOOD GROUP ANTIGEN IS EXPRESSED BY A 

UNIQUE SUBSET OF TASTE BUD CELLS 

Christy R.C. 1, Boughter J.D. 1, Smith D.V. 1 1Anatomy & Neurobiology, 

University of Tennessee Health Science Center, Memphis, TN 

Although mammalian taste cell types differ across species, most 

investigators recognize at least two classes of elongated, spindle-shaped 

cells: Type I (dark) and Type II (light) cells, based on their relative 

electron densities when stained with uranyl acetate. These cell types 

differ markedly in their morphology in transverse sections through the 

taste bud. A third cell type (Type III), which is electron lucent and 

round in transverse section like a Type II cell (and therefore a subtype 

of “light” cell), was first described in rabbit foliate taste buds as 

possessing synaptic connections with nerve fibers. Type III cells have 

also been described in rat and mouse vallate taste buds on the basis of 

specific antigen expression and ultrastructural similarity to rabbit Type 

III cells. Here we examine rat and mouse taste buds for 

immunocytochemical expression of several markers that delineate 

differences among light cell types, which, unlike Type I cells, are 

heterogeneous in their expression patterns. NCAM is expressed on a 

subset of Type III cells and α-gustducin on a subset of Type II cells, 

only some of which also express the Lewisb blood group antigen. The 

blood group A antigen co-localizes with α-gustducin on some cells 

(which do not express Lewisb ) and not others but does not label any 

NCAM- or PGP 9.5-positive cells. Combined with the work of others 

showing subtypes of Type III cells expressing combinations of PGP 

9.5, 5-HT and/or NCAM, these data provide additional evidence for the 

molecular complexity of mammalian taste bud cells. Supported by 

NIDCD DC00347 to DVS. 

48 


System 

PROLIFERATION OF LINGUAL MACROPHAGES AFTER 

UNILATERAL DENERVATION OF FUNGIFORM TASTE 

BUDS. 

Mccluskey L.P. 1, Rigsby C.S. 1 1Physiology, Medical College of 

Georgia, Augusta, GA 

Within days after unilateral chorda tympani nerve (CT) section, 

activated ED1+ macrophages are increased on both the sectioned and 

intact sides of the tongue. Activated macrophages release a variety of 

cytokines and growth factors, which are proposed to affect sodium taste 

function after neural injury. We hypothesized that local proliferation of 

ED1+ macrophages accounts for the dramatic increase observed after 

nerve section. SD specified pathogen-free rats received unilateral CT 

section or sham section on day 0. On day 1 or 2 post-section, rats were 

given an injection of BrdU (50 mg / kg i.p.) 6 hr prior to sacrifice. 

Paraffin sections were processed for double immunofluorescent staining 

with antibodies to BrdU and ED1. As previously observed, there was an 

increase in ED1+ macrophages at both day 1 and day 2 post-sectioning. 

However, while BrdU+ cells were also numerous throughout tongue, 

few cells were double-positive. Therefore, ED1+ macrophages do not 

appear to proliferate in the lingual environment in response to 

denervation. We next examined whether the increase in ED1+ 

macrophages might be due to proliferation of resting, resident ED2+ 

macrophages that convert to an activated phenotype. Yet there were 

also few ED2+ / BrdU+ cells after nerve section, suggesting that 

proliferation of ED2+ macrophages does not account for the increased 

ED1+ population at these time points. We are currently examining the 

possibility that circulating ED1+ cells enter the tongue in response to 

denervation. Resolving this issue will increase our understanding of 

potential immune mechanisms that regulate peripheral taste function. 

Supported by NIH grant 1 R01 DC005811-01A1. 

188 Slide [ ] Beidler Colloquium on Taste Transduction 

THE MAMMALIAN AMILORIDE-INSENSITIVE (AI) NON- 

SPECIFIC SALT TASTE RECEPTOR IS A VANILLOID 

RECEPTOR-1 (VR-1) VARIANT 

Lyall V. 1, Heck G.L. 1, Vinnikova A.K. 2, Ghosh S. 2, Phan T.T. 1, Bigbee 

J.W. 3, Desimone J.A. 1 1Physiology, Virginia Commonwealth 

University, Richmond, VA; 2Internal Medicine, Virginia Commonwealth 

University, Richmond, VA; 3Anatomy and Neurobiology, Virginia 

Commonwealth University, Richmond, VA 

The AI non-specific salt taste receptor is the predominant transducer 

of salt taste in some mammalian species, including humans. The 

physiological, pharmacological and biochemical properties of the AI 

salt taste receptor were investigated by RT-PCR, direct measurement of 

unilateral apical Na + fluxes in polarized rat fungiform taste receptor 

cells (TRCs), and chorda tympani (CT) nerve recordings to lingual 

stimulation with NaCl, KCl, NH Cl and CaCl , in both the rat model 

4 2 

and the VR-1 knockout mouse model. We report that the AI salt taste 

receptor is a constitutively active non-selective cation channel derived 

from the VR-1 gene. It accounts for all of the AI CT response to Na + 

salts and part of the response to K + , NH4 + , and Ca2+ salts. It is activated 

by vanilloids (resiniferatoxin and capsaicin) and temperature (>38oC), and is inhibited by VR-1 antagonists (capsazepine and SB-366791). In 

the presence of vanilloids, external H + and ATP lower the temperature 

threshold of the channel. This allows for increased salt taste sensitivity 

without an increase in temperature. VR-1 knockout mice demonstrate 

no functional AI salt taste receptor and no salt taste sensitivity to 

vanilloids and temperature. We conclude that the mammalian AI nonspecific 

salt taste receptor is a VR-1 variant. Supported by NIDCD 

Grants DC-02422 and DC-00122.


RESIDUAL RESPONSES TO BITTER, SWEET AND UMAMI 

COMPOUNDS IN TRPM5 KNOCKOUT MICE 

Damak S. 1, Rong M. 2, Kokrashvilli Z. 2, Yasumatsu K. 3, Glendinning 

J.I. 4, Ninomiya Y. 3, Margolskee R.F. 2 1Nestle Research Center, 

Lausanne, Switzerland; 2Physiology and Biophysics, Mount Sinai 

School of Medicine, New York, NY; 3Kyushu University, Fukuoka, 

Japan; 4Barnard College, Columbia University, New York, NY 

To determine the role of Trpm5 in taste responses in vivo, we 

generated Trpm5 knockout (KO) mice by homologous recombination in 

ES cells. Two bottle preference tests of wildtype (WT) vs. Trpm5 KO 

mice showed reduced, but not abolished, responses of the KO mice to 

the bitter compounds quinine and denatonium. By this test the Trpm5 

KO mice were indifferent to concentrations of quinine and denatonium 

up to 1 mM and 10mM, respectively, then showed strong avoidance to 

higher concentrations. A brief access test using a gustometer confirmed 

that high concentrations of denatonium were aversive to the KO mice. 

The KO mice were indifferent to low concentrations of denatonium and 

to all concentrations of quinine. With sweet compounds, two bottle 

preference tests of Trpm5 KO mice showed reduced preference for 

sucrose and the artificial sweetener SC45647. However, in the brief 

access test, Trpm5 KO mice were indifferent to these compounds. Postingestive 

effects (two bottle preference test) and/or lower sensitivity 

(gustometer) may affect the behavioral responses elicited by these 

behavioral tests and explain this apparent discrepancy. Gustatory nerve 

recordings are in progress to further investigate this. The Trpm5 KO 

mice showed residual preference for 100mM and 300mM MSG 

(umami) by two bottle preference test, but not by lickometer. Both 

behavioral tests showed that the Trpm5 KO mice avoid 1 M MSG. The 

behavioral responses to HCl elicited by either test were identical in the 

KO and WT animals. Together, these results indicate that Trpm5 is an 

important component of the taste response to bitter, sweet and umami 

compounds, but that additional Trpm5-independent response pathways 

exist. 

49 


DUAL REGULATION OF THE TASTE TRANSDUCTION ION 

CHANNEL TRPM5 BY CA2+ AND PIP2 

Liman E.R. 1, Liu D. 1 1Neurobiology, University of Southern California, 

Los Angeles, CA 

The transduction of taste is a fundamental process that allows 

animals to discriminate nutritious substances from those that are 

noxious. Three taste modalities, bitter, sweet and amino acid, are 

mediated by G-protein coupled receptors. Recent evidence suggest that 

these receptors signal through a common transduction cascade: 

receptors activate phospholipase C (PLC), leading to a breakdown of 

phosphatidyinositol-4,5-bisphosphate (PIP ) into diacylglycerol (DAG) 

2 

and inositol 1,4,5-trisphosphate (IP ), which causes release of Ca 3 2+ 

from intracellular stores. The ion channel, TRPM5, is essential for 

transduction of bitter, sweet and amino acid tastes, but the mechanisms 

which it is activated are not well understood. We find that when 

expressed heterologously in HEK 293, TRPM5 forms an outwardly 

rectifying cation channel that is activated downstream of Gq-coupled 

membrane receptors. In excised patches from CHOK1 cells expressing 

TRPM5, channel activity was induced by micromolar concentrations of 

intracellular Ca2+ , but not by DAG or IP . Sustained exposure to Ca 3 2+ 

desensitized TRPM5 channels. Application of the membrane 

phospholipid, PIP enhanced the current following desensitization, but 

2 

not before desensitization, suggesting that loss of PIP may underlie 

2 

desensitization. These data allow us to propose a model for G proteincoupled 

taste transduction in which Ca2+ serves as the second 

messenger linking receptor signaling to membrane depolarization. 

Supported by grants from the NIDCD (DC04564 and DC05000). 


DEORPHANIZATION AND FUNCTIONAL SNP ANALYSIS OF 

TAS2R BITTER TASTE RECEPTORS 

Bernd B. 1, Christina K. 1, Winnig M. 1, Slack J. 2, Breslin P.A. 3, Reed 

D.R. 4, Tharp C.D. 4, Kim U. 5, Drayna D. 5, Meyerhof W. 1 1Molecular 

Genetics, German Institute of Human Nutrition Potsdam-Rehbruecke, 

Nuthetal, Germany; 2Givaudan Flavors Corp., Cincinnati, OH; 3Monell 

Chemical Senses Center, Philadelphia, PA; 4Monell Chemical Senses 

Center, Philadelphia, OH; 5NIDCD/NIH, Rockville, MD 

Taste sensitivities to different bitter compounds vary between 

individuals. The most prominent example for genetically determined 

taste differences is the bitter taste of phenylthiocarbamide (PTC) and 6- 

N-propylthiouracil (PROP). A recently published study (Kim et al., 

Science 299, 1221-1225) showed a good correlation between the human 

PTC taster and non-taster phenotype and three single nucleotide 

polymorphisms (SNPs) in the hTAS2R38 gene, suggesting that these 

SNPs might cause the individual taste differences for PROP, PTC, and 

various other chemically related bitter compounds. 

Using functional expression and calcium imaging (Bufe et al., Nature 

Genetics 32, 397-401) we demonstrated that the hTAS2R38 taster 

variant can be activated by PTC. In addition we identified ligands for 

four other human bitter taste receptors hTAS2R10, hTAS2R16, 

hTAS2R43, and hTAS2R44. Analysis of the human genome SNP 

database and own sequencing efforts so far revealed 14 non-conserved 

SNPs in the coding region of these receptors. Using site directed 

mutagenesis we created corresponding receptor variants and are 

studying their effects in our heterologous expression system. Initial 

results revealed that several of the hTAS2R38 SNPs altered the receptor 

function.

192 Symposium [ ] Olfaction and Neurodegenerative 

Disorders 

OLFACTION AND NEURODEGENERATIVE DISORDERS 

Doty R. 1 1Smell and Taste Center, University of Pennsylvania, 


Numerous major neurological disorders are associated with olfactory 

dysfunction. Indeed, the first clinical sign of such diseases as 

Alzheimer´s disease and idiopathic Parkinson´s disease appears to be 

decreased olfactory function. In the case of Parkinson's disease, the 

prevalence of smell loss is greater than the prevalence of tremor, and is 

essentially equivalent to that of the other major motoric signs of the 

disease. Importantly, not all neurological or neurodegenerative 

disorders are associated with smell loss. Hence, olfactory testing can 

aid in the differential diagnosis of a number of disorders commonly 

confused on initial presentation, including Alzheimer's disease vs. 

major affective disorder, and Parkinson's disease vs. progressive 

supranuclear palsy. The olfactory evaluation of at-risk individuals, 

including relatives, may prove to be of considerable clinical value for 

initiating neuroprotective therapy early in disease development. This 

symposium provides an up-to-date overview of relationships between 

olfactory function and four major neurological diseases. The 

participants and discussants represent active researchers in this field, 

and bring a variety of perspectives and a wealth of information to this 

topic. 


Disorders 

LONGITUDAL EVALUATION OF OLFACTORY FUNCTION 

IN ALZHEIMER'S DISEASE 

Devanand D.P. 1, Tabert M.H. 1 1Psychiatry, Columbia 

University/NYSPI, New York, NY 

We evaluated the predictive utility of olfactory deficits in patients 

with minimal to mild cognitive impairment (MMCI). 150 outpatients 

presenting to a Memory Disorders Center were recruited and followed 

at 6-month intervals. 63 group-matched controls were followed 

annually. Patients had a mean age of 67 (SD 9.8) and mean education of 

15 (SD 4.2) years. Mean age for controls was 65 (SD 9.3) and mean 

education was 16 (SD 2.6). UPSIT scores were lower in patients (mean 

31 SD 6.4) than controls (mean 34 SD 4.2). Baseline UPSIT scores 

were lower in converters to Alzheimer´s Disease (AD; n=35, mean 26 

SD 8.2) than non-converters (mean 33, SD 4.7) (mean follow-up=39 

months). In Cox regression analyses, low olfaction scores predicted AD 

(Wald chi2=15.9, p < .0001). The UPSIT score remained a significant 

predictor (p < .0003, relative risk=0.9 per UPSIT point change) even 

when age, sex, and education were included as covariates, and when 

MMS was included as a covariate. ApoE e4 genotype did not differ 

between non-converters (22%) and converters (28%). UPSIT scores 

were correlated with right hippocampal volume (r=0.20, p < .03). In 

Cox regression analyses, low olfaction scores predicted outcome (Wald 

chi2=10.6, p < .002, relative risk=0.92 per point change) even when 

hippocampal volume, age, and gender were included. Olfactory deficits 

predicted conversion to AD in patients with MMCI, even after 

controlling for demographic, cognitive, and brain volumetric predictors. 

In addition, odor-induced fMRI activation is also being examined in 

controls and AD and MMCI patients. 

Grants: AG17761 (P.I. Devanand), K01AG21548 (P.I. Tabert) and 

from the Alzheimer´s Association (P.I. Devanand) 

50 


Disorders 

OLFACTORY SYSTEM DYSFUNCTION IN SCHIZOPHRENIA 

Moberg P.J. 1, Turetsky B.I. 1 1Psychiatry, University of Pennsylvania, 


Psychophysical studies of olfaction have documented impairments in 

odor detection thresholds, identification, memory and hedonics in 

patients with schizophrenia. Similar deficits exist in non-ill family 

members. Despite evidence of behavioral impairment, there is little 

evidence that the neuroanatomical or neurophysiological substrates of 

olfaction are abnormal. 

We have conducted a series of studies examining the structural and 

functional integrity of the olfactory system in patients and their firstdegree 

relatives. 1)Using acoustic rhinometry, we have shown a 

reduction of the left-posterior nasal cavity in male patients. 2)Using 

high-resolution MRI, we found bilateral olfactory bulb volume 

reductions in patients, and unilateral right sided reductions in family 

members. 3)Following parcellation of the anterior ventromedial 

temporal lobe into perirhinal, entorhinal and temporal polar regions, 

patients exhibited selective gray matter volume reductions in the 

perirhinal and entorhinal areas bilaterally. 4)Using air-dilution 

olfactometry, both patients and non-ill family members were observed 

to exhibit dose-dependent abnormalities in the olfactory evoked 

potential. 

There are thus primary structural and functional abnormalities in the 

olfactory system, which underlie the behavioral deficits seen in 

schizophrenia. These abnormalities appear to denote an endophenotypic 

genetic vulnerability marker, rather than an index of either clinical 

disease status or treatment. A greater understanding of the neurobiology 

of these olfactory deficits could offer clues to both the basic 

neuropathology and the genetic precursors of this disorder. 

Supported by MH63381(PJM), MH59852(BIT), & NARSAD(PJM).


Disorders 

OLFACTORY DYSFUNCTION IN MULTIPLE SCLEROSIS 

Doty R.L. 1 1Smell and Taste Center, Department of 

Otorhinolaryngology: Head and Neck Surgery, University of 

Pennsylvania, Philadelphia, PA 

For many years it was assumed that multiple sclerosis (MS) was 

unaccompanied by olfactory dysfunction. While several early studies, 

including a pioneering study by Ansari in 1976, failed to find any 

olfactory deficits in this disease, more recent studies from our group 

have clearly demonstrated that some MS patients exhibit olfactory loss. 

In 1984 we reported that 23% of a group of 31 MS patients exhibited 

smell dysfunction, as measured by the University of Pennsylvania 

Smell Identification Test (UPSIT). A decade later we presented clinical 

cases in which smell loss was a presenting sign of MS. In a subsequent 

series of studies in the late 1990´s, we demonstrated that such loss was 

correlated with the number of MS-related plaques in subtemporal and 

subfrontal brain regions, but not in other brain regions. Moreover, we 

showed that olfactory function waxes and wanes longitudinally in 

accordance with the number of active plaques in these brain regions. In 

this presentation, I review these studies, as well as initial results of a 5year-long 

study of 73 MS patients and controls, in which a range of 

sensory and neuropsychological tests were administered, including ones 

tapping olfactory (i.e., odor identification, detection & discrimination), 

gustatory (e.g., regional taste identification), auditory (e.g., pure tone 

thresholds, competing words, auditory figure-ground), vestibular (e.g., 

Rhomberg eyes open & closed tasks), and cognitive (e.g., Wechsler 

Memory Scale-Revised; National Adult Reading Test; Wisconson Card 

Sorting Test) functions. 

Supported by grant RO1 DC 02974 from the National Institute on 

Deafness and Other Communication Disorders. 


Disorders 

OLFACTION IN PARKINSONISM 

Hawkes C. 1 1Essex Neuroscience Centre, Essex, United Kingdom 

There has been gradual increase of interest in olfaction since it was 

realised that anosmia was a common feature of idiopathic Parkinson's 

disease (IPD) and Alzheimer-type dementia (AD). It is an intriguing 

possibility that the first sign of a disorder hitherto regarded as one of 

movement or cognition may be that of disturbed smell sense. In this 

review of parkinsonian syndromes the following observations can be 

made: 1) olfactory dysfunction is frequent and often severe in IPD and 

may precede motor signs of IPD 2) normal smell identification in IPD 

is rare and should prompt review of diagnosis unless the patient is 

female with tremor dominant disease. 3) olfactory impairment in 

suspected progressive supranuclear palsy or corticobasal degeneration 

is atypical and should likewise provoke diagnostic review. 4) impaired 

smell sense is seen in some patients at 50% risk of parkinsonism 5) 

biopsy of olfactory nasal neurons reveals non-specific changes in IPD 

and at present will not aid diagnosis. 

51 

197 Poster [ ] Development of the Gustatory System 

EGF SIGNALING IN PATTERNING FUNGIFORM PAPILLAE 

IN EMBRYONIC RAT TONGUE 

Liu H. 1, Mistretta C. 1 1School of Dentistry, University of Michigan, Ann 

Arbor, MI 

In previous experiments to understand how papillae form in patterns 

on the embryonic tongue, we demonstrated roles for the morphogen, 

sonic hedgehog (Shh) in fungiform papilla development. Fungiform 

papillae form in doubled numbers and atypical posterior locations in 

tongue cultures when Shh signaling is selectively disrupted with the 

alkaloid, cyclopamine. To further understand molecular regulation and 

interactions in papilla formation, we are studying effects of epidermal 

growth factor, EGF. A polyclonal antibody to EGF receptor (EGFR) 

was used to immunolocalize EGFR in rat embryo tongues at gestational 

days (E) 13-18. Also, in whole tongue cultures begun at E14, we 

examined effects of exogenous EGF on fungiform papilla development 

and on the cyclopamine-induced change in papilla patterning. EGFR 

localized in all layers in the dorsal epithelium of embryonic rat tongue 

at all ages examined. Immunoproducts were weak and homogeneous in 

the tongue epithelium at E13-E14. Signals became progressively more 

intense in the inter-papilla space, but not within the papilla epithelium, 

in association with papilla development from E15-E18. In E14+2 day 

cultures, EGF dose-dependently decreased the number of fungiform 

papillae while stimulating epithelial proliferation. Moreover, preincubation 

with EGF, followed by culture with EGF plus cyclopamine, 

prevented the cyclopamine-induced change in papilla pattern. The data 

demonstrate that EGF signaling plays an important role in spacing of 

fungiform papillae in embryonic tongue, and interacts with Shh 

signaling in regulating development of papilla pattern. Supported by 

NIH NIDCD Grant DC000456 to CMM. 


TASTE BUD PRIMORDIA DEVELOP IN RODENT TONGUE 

CULTURES 

Walters E. 1, Mbiene J. 2 1Department of Biochemistry and Molecular 

Biology, Howard University, Washington, DC; 2Department of 

Biomedical Sciences, Texas A&M University System, Dallas, TX 

Lingual taste buds form within papillae in mammals. We are 

studying the molecular aspects of taste bud differentiation during 

development. Keratin 8 is expressed in epithelial cell clusters in 

distinctive patterns across the developing tongue in mouse embryos 

before the innervation of tongue epithelium. To learn whether keratin 8 

expression proceeds in vitro as in vivo, we examined the expression 

patterns of keratin 8 in mouse tongue cultures. Tongue or lower jaw 

explants were taken from gestational days 11.5 and 12.5 mouse 

embryos and maintained at liquid-gas interface in conventional organ 

cultures. Explanted tongues were harvested after 1-6 days in culture and 

assayed for keratin 8 by immunocytochemistry. In E11.5 and 12.5 

mouse tongue explants, keratin 8 is broadly expressed in the lingual 

epithelium, as in vivo. Over the next 24-48 hours, keratin 8 becomes 

restricted to clusters of cells located in the center of epithelial placodes. 

Surprisingly, keratin 8 continues to be expressed in few clusters after 6 

days of culture. These results establish that much of taste bud 

development is nerve dependent in mammals. I am currently examining 

the gene repertoire expressed in tongue placodes that may possibly play 

a role in the determination of taste buds.Grant sponsor: NIDCD; Grant 

number: DC03503


IDENTIFICATION OF DEVELOPMENTALLY REGULATED 

GENES EXPRESSED IN TASTE BUDS 

Iwatsuki K. 1, Watanabe A. 2, Aburatani H. 2, Margolskee R. 3 1Physiology 

& Biophysics, Mount Sinai School of Medicine, New York, NY; 

2RCAST, The University of Tokyo, Tokyo, Japan; 3Howard Hughes 

Medical Institute, Mount Sinai School of Medicine, New York, NY 

During their differentiation and development, taste cells express a 

variety of molecules in spatially and temporally regulated fashion. 

Although several markers selectively expressed in mature taste cells 

have been identified, few markers of developing taste cells are known, 

making it difficult to study how taste cells develop and mature from 

stem cells and precursor cells. 

To search for genes selectively expressed during mouse taste cell 

development we used Representational Difference Analysis (RDA) and 

Affymetrix gene chip analysis to compare mRNAs from circumvallate 

(CV) papillae ("taste") vs. surrounding non-sensory lingual epithelial 

tissue ("non-taste"). Most of the genes cloned by RDA, including small 

proline rich proteins and mesothelin, were also found by Affymetrix 

gene chips. Selective expression of these genes was confirmed by 

semi-quantitative RT-PCR. Those genes confirmed to be differentially 

expressed in taste vs. non-taste were examined by in situ hybridization. 

To date, we have identified more than 20 genes, including Trpm5 and G 

gamma 13, that are selectively expressed in adult taste cells. We 

carried out in situ hybridization on a series of CV sections from early 

through mature stages of taste bud development to examine temporal 

and spatial patterns of expression of these genes. We have identified 

several marker genes for taste cells which were expressed in one of two 

patterns: 1) early through late stages, 2) only in late stage of taste cell 

development. 


RELATIONSHIP BETWEEN EXPRESSION OF 

POSTSYNAPTIC DENSITY PROTEIN 95 (PSD-95) AND THE 

DEVELOPMENT OF TASTE BUDS IN THE 

CIRCUMVALLATE PAPILLAE OF RAT COMPARED WITH 

G-GUSTDUCIN AND PROTEIN GENE PRODUCT 9.5. 

Ueda K. 1, El Sharaby A. 2, Wakisaka S. 2 1Psychology, University of 

Virginia, Charlottesville, VA; 2Dept. of Oral Anat.& Deverop. Biol. 

Grad. School of Dentistry, Osaka University, Suita, Osaka, Japan 

It is well known that neurotrophic factors are necessary for 

formation, development and maintenance of mammalian taste buds, and 

that type III taste cells have synaptic connections with gustatory nerves. 

However it is unclear how synapses develop in taste buds. In this study 

we examined the distribution of postsynaptic density protein 95 (PSD- 

95) immunohystochemically in circumvallate papillae (CVP) in rats 

aged 0, 1, 2, 4, 5, 7, 14, 21, 28 days postnatal and in adults. At 

adulthood, strong PSD-95-like immunoreactivity (PSD-95-LI) existed 

around the taste pore and some of them overlapped with neuron and 

type III taste receptor cell specific gene, protein gene product 9.5 (PGP 

9.5). Type II cells are typically viewed as making contacts with nerve 

fibers, but they do not make classical synapses. However we found that 

some cells having Gα-gustducin-LI, considered as a marker of type II 

cells, also had PSD-95-LI. Developmentally, many taste buds existed in 

the CVP at birth, but PSD-95-LI did not occur until postnatal day 5. 

Thereafter, the density of PSD-95-LI increased progressively until it 

was similar to adults between PN 21-28 days. These results suggest that 

there may be subtypes of receptor cells based on the presence of 

synapses. Further, functional synaptic contacts in the CVP do not 

mature until after 3rd postnatal week. 

52 


NEUROTROPHIC FACTORS REGULATE THE SENSITIVITY 

OF GENICULATE AXONS TO SEMA3A DURING 

INNERVATION 

Saldanha J. 1, Vilbig R. 1, Rochlin M.W. 1 1Biology, Loyola University of 

Chicago, Chicago, IL 

Geniculate axons begin to penetrate the rat dorsal lingual epithelium 

at E17, followed by trigeminal axons (Farbman & Mbiene, J Comp 

Neurol 306:172-186), despite the presence of epithelial Sema3A 

mRNA. Trigeminal axons are repelled by Sema3A in vitro through E18 

(Dillon et al, ibid, 470:13-24), suggesting that Sema3A repellent 

activity or sensitivity to Sema3A is regulated in vivo. The neurotrophic 

factors that stimulate geniculate axon outgrowth in collagen gels and 

the response of this outgrowth to Sema3A during late embryonic stages 

are not known. BDNF, NT4, GDNF, and NGF (15-25 ng/ml) stimulate 

axon outgrowth above control media levels, although the NGF effect 

was small. BDNF stimulated the most rapidly advancing outgrowth, 

NT4 the slowest. In contrast to our results with the E18 trigeminal 

ganglion, Sema3A-transfected COS7 cells did not repel BDNF- (N=14) 

and GDNF- (N=9) stimulated outgrowth compared to control 

transfected COS7 cells (N=10 for each). However, NT4-stimulated 

outgrowth (N=17) was repelled (p

203 Slide [ ] Development of the Gustatory System 

TASTE PLACODES ARE PRIMARY TARGETS OF EARLY 

GENICULATE BUT NOT TRIGEMINAL PERIPHERAL 

NERVE ENDINGS IN THE DEVELOPING TONGUE OF 

MOUSE EMBRYOS. 

Mbiene J. 1 1Department of Biomedical Sciences, Texas A&M 

University System, Dallas, TX 

The establishment of a reproducible pattern of connectivity is as 

essential to neuron´s function as its physiological properties. Until 

recently innervation of gustatory papillae was thought to occur after 

their initial morphogenesis. However, new results from mammals 

indicate that much of molecular markers of papilla development are 

expressed prior to their overt formation. Given that markers of taste bud 

genesis begin to be expressed before papilla morphogenesis or its 

completion, we hypothesized that lingual epithelial placodes (which 

later will harbor the embryonic taste buds) are specific targets for taste 

afferents. To test this idea, we traced chorda tympani and lingual nerves 

with different lipophilic dyes and compared the patterns of their 

terminal arbors in tongues of mouse embryos from E11.5 to 14.5. The 

results indicate that chorda tympani, in contrast to lingual nerve fibers, 

pioneer the tongue at E11.5. Over the next 24 hours, at E12.5, the 

tongue epithelium is still not contacted by nerves but the ramification 

patterns of both nerves in the tongue are identical. At E13.5 (when the 

first taste buds are apparent) chorda tympani axons make contacts with 

the epithelial placodes under which they exhibited distinctive terminal 

arbors. At E14.5 (when the fungiform papillae first form) chorda 

tympani enter and reach the apical epithelium of the papilla where the 

embryonic taste buds form. These results indicate that taste buds form 

at the same time as they are innervated and will be discussed in the 

context of the current view of non-neural induction of taste buds. Grant 

sponsor: NIDCD; Grant number: DC03503 


ROLES FOR HEDGEHOG PROTEINS IN SUPPORTING 

NEURON SURVIVAL AND NEURITE EXTENSION IN 

EMBRYONIC GENICULATE AND TRIGEMINAL GANGLIA 

Bai L. 1, Mistretta C. 1 1School of Dentistry, University of Michigan, Ann 

Arbor, MI 

Sonic hedgehog (Shh) and other Hedgehog (Hh) proteins have 

known roles in regulating proliferation of neuron precursors, neuron 

differentiation and neurite outgrowth, and Schwann cell – neuron 

interactions. Because Shh is intensely localized in developing papilla 

placodes and fungiform papillae in embryonic rat tongue, we 

hypothesized that Shh, and/or other Hh proteins, also would have roles 

in regulating neuron number and neurite extension in the geniculate 

(gg) and trigeminal (tg) ganglia, which innervate these papillae. Ganglia 

were dissected from gestational day 13 and 16 rat embryos and 

explanted onto matrix-coated coverslips. Gg and tg cultures were 

maintained in standard medium (B27), with or without neurotrophins, 

BDNF or NGF, for 2 to 5 days. To test roles for Hh proteins in ganglion 

cultures, we added the alkaloid cyclopamine (CYCL), a specific blocker 

of hedgehog signaling at the receptor complex, to B27, BDNF or NGF 

culture media. In all cultures with CYCL, there were decreased 

numbers of ganglion neurons, and the extent of neurite outgrowth was 

reduced. CYCL effects were concentration – dependent (from 1 to 10 

uM). With immunohistochemistry we demonstrated that gg and tg 

neurons contain the hedgehog receptor proteins, patched and 

smoothened, both in cultures and in vivo. Another molecule in the 

signaling pathway, hedgehog - interacting protein, also was 

immunolocalized in the ganglia. The data provide evidence that 

members of the Hedgehog family support survival and neurite 

extension of embryonic gg and tg neurons. Supported by NIH NIDCD 

Grant 000456. 

53 


GUSTATORY PHENOYPE IN DOUBLE NEUROTROPHIN 

KNOCKOUT MICE 

Nosrat I. 1, Agerman K. 2, Ernfors P. 2, Nosrat C.A. 1 1Laboratory of Oral 

Neurobiology, Biologic & Materials Sciences, University of Michigan, 

Ann Arbor, MI; 2Unit of Molecular Neurobiology, MBB, Karolinska 

Institutet, Stockholm, Sweden 

BDNF and NT-3, but not NT-4, are expressed in developing 

gustatory papillae and taste buds and participate in establishing the 

gustatory and somatosensory innervation of the tongue. BDNF, NT-3 

and NT-4 null mutated mice show deficits in their lingual gustatory and 

somatosensory innervation. 

We have generated double neurotrophin knockout mice and have 

analyzed the differences in the gustatory phenotypes of wild type, 

BDNF, BDNF/NT-3 and BDNF/NT-4 mice. Because BDNF/NT-3 and 

BDNF/NT-4 mice die at birth, we have focused our study on newborn 

animals. We have focused the present study on the number, average 

size and innervation of the gustatory papillae in these mice. Fungiform 

papillae numbers were decreased significantly in all mutant mice while 

BDNF/NT-3 mice exhibited the most severe phenotype. Size 

measurements revealed a slight decrease in the size of BDNF and 

BDNF/NT-4 fungiform papillae, but the strongest significant size 

reduction was observed in BDNF/NT-3 mice. Innervation 

measurements followed the same trend, with BDNF mice having the 

least severe loss of innervation, followed closely by BDNF/NT4 mice 

while BDNF/NT-3 mice exhibited the most severe phenotype. Taken 

together, we propose NT-3 dependent innervation plays crucial roles in 

maturation and maintenance of fungiform papillae while NT-4 

phenotype is mimicked by BDNF in the anterior part of the tongue. 


NEURONAL DEATH IN THE RAT GENICULATE GANGLION 

DURING DEVELOPMENT 

Carr V.M. 1, Sollars S.I. 2, Farbman A.I. 1 1Neurobiology and Physiology, 

Northwestern University, Evanston, IL; 2Psychology, University of 

Nebraska Omaha, Omaha, NE 

The geniculate ganglion provides sensory innervation to taste buds 

on the anterior tongue and the palate, and to the skin of the ear. During 

vertebrate development other sensory ganglia undergo a period when 

neuron cell death occurs, often because of insufficient target-derived 

trophic substance for maintenance of all ganglionic neurons. We 

examined neuronal death in the geniculate ganglion to try to determine 

when critical developmental events might occur that would be related to 

the survival or death of geniculate neurons. Thus far, 10 micron 

histological sections of geniculate ganglia from fetal (E17-E22) and 

newborn (P1-P3) rats have been examined following fixation in 4% 

paraformaldehyde and standard staining procedures. Earlier stages are 

currently under investigation. At each age total numbers of neurons 

and pycnotic neurons were counted in 8 ganglia. The average incidence 

of pycnotic neurons at E17 was 9% of total neurons. The percentage 

then decreased progressively, leveling off at 0.2% by E22. Findings 

suggest that critical events related to neuronal survival occur from at 

least E17 to E21, when neuronal death is elevated. Trophic substances 

required for survival might be present in limited amounts so that only 

those neurons that receive sufficient amounts will survive. These 

trophic factors could originate from several sources, including the 

neurons themselves, the supporting cells around the neurons in the 

ganglion, the peripheral targets or the central targets of the neuronal 

projections, or a combination of sources. Supported by NIDCD 

Grants 04837 (AF) and 04846 (SS).

207 Poster [ ] Bitter Taste 

BLOCKING GLUTAMATE RECEPTORS IN THE 

PARABRACHIAL NUCLEUS REDUCES AVERSIVE 

OROMOTOR RESPONSES TO QUININE IN CONSCIOUS 

RATS 

King M.S. 1, Keller G.S. 1, Uflacker A.B. 1 1Biology, Stetson University, 

DeLand, FL 

Microinjection of glutamate into the classic gustatory region of the 

parabrachial nucleus (PBN), the 'waist' region (W), in conscious rats 

elicits ingestive oromotor behaviors, but the exact functional role of 

glutamate in W is unclear. This pilot study was designed to examine 

taste reactivity responses during oral infusion of tastants while blocking 

glutamate neurotransmission in W. Cannula (Plastics One) were placed 

bilaterally into W in 8 male Wistar rats. The cannula were connected to 

osmotic pumps (Alzet) that were filled with either aCSF (n=3) or 

kynurenate (KYN, an ionotropic glutamate receptor antagonist) in aCSF 

[250 (n=2), 10 (n=2) or 2.5mM (n=1)]. The pumps delivered .25µl/hr 

for 7 days. Rats also were implanted with intra-oral cannula for the 

infusion of tastants. After recovery from surgery and habituation to the 

behavioral arena, rats were videotaped on two successive days during 1min 

(.233ml) oral infusions of dH2O, .1M NaCl and .03M HCl on the 

first day, and dH2O, .1M sucrose and .003M quinine hydrochloride on 

the second day. Ingestive oromotor responses to all chemicals were 

similar in all groups, however aversive responses to quinine (e.g. gapes) 

were dramatically reduced in rats receiving infusions of 250mM KYN 

(mean of 56 vs 2, p 

+0.9) but not with responses to MgCl . These results suggest overlap in 

2 

the coding of bitter taste information for the former three compounds 

but heterogeneity in the mechanisms for quinine vs. bitter salts, 

consistent with taste discrimination studies in rats. Additional bitter 

stimuli will be tested. Supported by NIH DC00353. 


PLC2 KNOCK-OUT MICE DISPLAY LICK AVOIDANCE TO 

HIGH CONCENTRATIONS OF QUININE AND DENATONIUM 

Dotson C.D. 1, Richter T.A. 2, Roper S.D. 2, Spector A.C. 1 1Department of 

Psychology and Center for Smell and Taste, University of Florida, 

Gainesville, FL; 2Department of Physiology and Biophysics, and 

Neuroscience Program, University of Miami, Miami, FL 

The T1R and T2R families of taste receptors apparently mediate taste 

receptor cell responsiveness to “sweet” and “bitter” compounds, 

respectively. Yet these two distinct families are believed to share key 

components of their signaling pathways, namely TRPM5 ion channels 

and an isoform of phospholipase C (PLCβ2). There is evidence that 

mutant mice lacking either PLCβ2 or TRPM5 are completely 

unresponsive to these compounds. We sought to confirm the behavioral 

response characteristics of PLCβ2 knock-out (KO) mice and wild-type 

(WT) controls by using a brief-access taste test. Unconditioned licking 

responses of KO and WT mice were measured to sucrose (S), sodium 

chloride (N), quinine hydrochloride (Q), denatonium benzoate (D), and 

citric acid (C). KO mice were unresponsive to S, whereas WT mice 

showed concentration-dependent increases in licking. The 

concentration-response functions of KO mice were shifted to the right 

for both Q and D, but these animals nonetheless clearly showed lick 

suppression at higher concentrations. There were no significant 

differences between the C concentration-response functions from WT 

and KO mice. The results for N were somewhat more complex, but 

differences between WT and KO mice were modest. Thus mice can 

respond to higher concentrations of Q and D in the absence of PLCβ2 

suggesting that these “bitter” stimuli can activate additional 

transduction pathways that do not depend on this enzyme. Supported by 

R01-DC01628 (ACS) and R01-DC00374 (SDR).


FUNCTIONAL CHARACTERIZATION OF HUMAN T2R 

BITTER RECEPTORS. 

Sainz E. 1, Battey J.F. 1, Northup J.K. 1, Sullivan S.L. 1 1National Institute 

on Deafness and Other Communication Disorders, National Institutes 

of Health, Rockville, MD 

To characterize the functional properties of members of the human 

T2R family of bitter receptors, we are using an in vitro reconstitution 

assay. Baculoviral expression vectors were constructed with the human 

T2R genes and the mouse cycloheximide receptor gene, mT2R5. 

Western analyses with cellular membranes isolated from insect cells 

infected with these baculoviruses indicate that the membranes are 

highly enriched in bitter receptors. To validate our methods, we 

demonstrated functional reconstitution of the mT2R5 receptor by the 

addition of cycloheximide and purified G proteins to mT2R5-enriched 

membranes, as previously reported. We are currently screening orphan 

members of the hT2R family with a panel of 60 bitter-tasting 

compounds to uncover additional ligand-receptor interactions. Thus far, 

we have identified a bitter receptor that selectively responds to 

denatonium and another receptor that displays a broader response 

profile, responding to several of the bitter-tasting compounds tested. 

The pharmacophore for the seemingly more promiscuous receptor is 

under investigation. Given that the identities and concentrations of both 

the ligands and G proteins added in the assay can be controlled, this 

approach should allow the quantitative assessments of the ligand 

binding properties and the G protein selectivities of these receptors. 

This work is supported by the Division of Intramural Research, 

NIDCD/NIH/DHHS. 

212 Slide [ ] Bitter Taste 

THE EVOLUTIONARY DIVERSITY OF BITTER TASTE 

Hettinger T.P. 1, Frank M.E. 1 1Oral Diagnosis, Neurosciences, UCONN 

Health Center, Farmington, CT 

Bitter taste is a complex topic viewed from perspectives of chemical, 

receptor, behavioral and species diversity. Many chemically diverse 

compounds are bitter to humans, and multiple G-protein coupled 

receptors (GPCRs), the T2 candidate bitter receptors, have been 

identified. We are conducting a series of studies addressing which of 

those compounds may be “bitter” to golden hamsters (Mesocricetus 

auratus). Behavioral cross-generalizations indicate that the ionic 

denatonium and MgSO4, and non-ionic caffeine and sucrose 

octaacetate (SOA) have distinct sensory qualities to hamsters. In 

hamsters only the ionic stimuli activate the chorda tympani nerve (CT) 

and cross-generalize with quinine, the human bitter prototype. Some 

inbred strains of golden hamsters, e.g., ACNT, prefer nonionic SOA 

and caffeine, which taste bitter to humans. Hamster behavioral 

preference and CT neural thresholds for denatonium are 5 orders of 

magnitude higher than human thresholds. Thus, although denatonium 

may be “bitter” to hamsters and humans, the receptors are likely 

species-specific. Simple salts such as MgSO4 are also bitter and other 

mechanisms must be considered; nonetheless, candidate T2 GPCRs 

likely contribute to the observed bitter diversity within and across 

species. By analyzing nucleotide and amino-acid sequences published 

in the NCBI genetic database, we are working to develop models to 

recognize orthologous (between species) and paralogous (within 

species) variation among T2s in order to sort out bitter diversities. 

[Supported by NIH grant R01 DC04099] 

55 


HIGH RESOLUTION MAPPING OF THE BITTER TASTE 

SENSITIVITY LOCUS QUI 

Nelson T.M. 1, Munger S.D. 1, Boughter, Jr J.D. 2 1Anat & Neurobiology, 

Univ Maryland Sch Med, Baltimore, MD; 2Anat & Neurobiology, Univ 

Tennessee Hth Sci Ctr, Memphis, TN 

Although several genes have been implicated in the detection and 

transduction of taste stimuli, there is still a sizable gap in our 

understanding of the mechanisms of taste transduction and sensory 

coding, as well as how taste-related genes combine to underlie 

behavioral responsiveness. To better understand the genetic basis of 

bitter taste behavior, we have sought to identify genes that contribute to 

specific bitter taste sensitivities. Using a brief-access taste test, which 

minimizes non-gustatory variables, we determined the taste sensitivities 

of BXDTy recombinant inbred mouse strains (as well as their parental 

strains, C57BL/6J (B6) and DBA/2J (D2)) to several bitter stimuli. Our 

initial interval mapping of the BXDTy dataset confirmed a significant 

quantitative trait locus (QTL), Qui, for quinine taste sensitivity (e.g., 

Lush, 1986) on distal Chr 6. We have defined the physical interval that 

contains Qui. This interval includes a cluster of 24 Tas2r genes 

encoding T2R putative bitter taste receptors. Comparisons of the 

protein coding sequences across B6, D2 and BXDTy lines revealed 

distinct B6 and D2 alleles for a number of Tas2r genes; these allelic 

variants correlate with the taster status of individual BXDTy lines. 

These studies should facilitate the identification of major quantitative 

trait genes underlying bitter taste. Supported by NIDCD: 

DC005786(SDM), DC004935(JDB). 


RELATIONSHIP BETWEEN GENOTYPES OF THE TAS2R38 

GENE AND BITTER PERCEPTION IN 

Mennella J.A. 1, Pepino M.Y. 1, Kennedy J.M. 1, Mascioli K.J. 1, Reed 

D.R. 1 1Monell Chemical Senses Center, Philadelphia, PA 

The present study aimed to determine how variation in the TAS2R38 

gene influences the gustatory experience and preferences of children 

and adults for bitterness. To this aim, genotype and behavioral analyses 

were performed on 5- to 10-year-old children of African (43 girls, 44 

boys) or European (31 girls, 23 boys) descent and their mothers. 

Genomic DNA was extracted from cheek cells and alleles of the 

TAS2R38 gene were genotyped for the variant sites using allelespecific 

probes and primers. Forced-choice procedures embedded in the 

context of a game were used to determine sensitivity to the bitter taste 

of 6-n-propylthiouracil (PROP) during one test session and food habits 

during another. Regardless of race, alleles at TAS2R38 were 

significantly associated with PROP thresholds in children (p


BITTER TASTE MARKERS IDENTIFY SWEET AND 

ALCOHOL HEDONICS AND INTAKE 

Dinehart M.E. 1, Bartoshuk L. 2, Kinsley E. 1, Duffy V.B. 1 1Dietetics, 

University of Connecticut, Storrs, CT; 2Surgery, Yale University, New 

Haven, CT 

Human and animal data suggest connections between sweet and 

alcohol behaviors. We tested the ability of markers of variation in taste 

to identify preference for and intake of sweet foods and alcoholic 

drinks. Following the pioneering work of Fischer et al from the 1960s, 

taste variation was characterized by bitterness of 6-n-propylthiouracil 

(PROP) and quinine hydrochloride (QHCl). Bitterness varies 

genetically and across the lifespan (eg, hormonally, exposure to taste 

pathology). Adults (74 F, 51 M; 22-58 years) used the general Labeled 

Magnitude Scale to rate bitterness of 3.2 mM PROP and .32 mM QHCl 

and preference for sampled and survey sweet foods. Subjects reported 

alcohol and sweet food intake via frequency interview and energy from 

added sugar via food records analyzed with the USDA Pyramid 

Servings Database. Multiple regression revealed that lower preference 

for or intake of sweets and alcohol was predicted by greater PROP 

bitterness but lower QHCl bitterness. Although PROP and QHCl 

showed significant correlation, subjects fell into groups that were 

discordant in these bitters but nearly matched for sex. Those who tasted 

QHCl as more bitter relative to PROP (n=23) had significantly greater 

preference for and intake of sweets and greater alcohol intake than 

those who taste PROP as more bitter relative to QHCl (n=24). In 

summary, use of both bitter makers increased the ability to explain 

sweet and alcohol behaviors. Whether quinine bitterness reflects 

another genetic taste variant or an environmentally-mediated pattern of 

sensation is unknown. (NRICGP/USDA 2002-00788, NIH DC00283) 

216 Poster [ ] Olfactory Bulb: Coding 

INHIBITION OF ADENYLYL CYCLASE IN LOBSTER 

OLFACTORY RECEPTOR NEURONS ENHANCES CENTRAL 

RESPONSES TO ODORS 

Aggio J.F. 1, Daly K. 2, Ache B. 1 1The Whitney Laboratory, University of 

Florida, St. Augustine, FL; 2Dept. of Entomology, Ohio State 


Olfactory receptor neurons (ORNs) in some animals can be inhibited 

as well as excited by odorants. The question is whether such bipolar 

input is functionally significant in olfaction. Pharmacological 

intervention of the cyclic nucleotide signaling cascade in lobster ORNs 

selectively alters inhibitory responses to odorants. As a first step to 

addressing this question, we assessed the effect of blocking adenylyl 

cyclase (AC) peripherally on the output of the first olfactory relay, the 

olfactory lobe (OL), in a perfused lobster nose-brain preparation. We 

show that pharmacologically blocking AC in the periphery had no 

effect by itself, but could enhance the response of the OL to odorant 

mixtures, consistent with the predicted reduction in odorant-evoked 

inhibitory input that should follow AC blockade. Blocking AC could 

also enhance the response of the OL to single component odorants. 

Given earlier evidence that monomolecular odorants excite and inhibit 

different cells, the latter finding suggests that spontaneous activity in 

the ORNs may be sufficient to register peripheral inhibition in the OL 

in the absence of co-activation by other odorants. Our results suggest 

that inhibitory input to the olfactory periphery helps shape the output of 

the OL and, therefore, potentially contributes to the olfactory code. 

Supported by the McDonnell Foundation (BWA, KCD) and the 

NIDCD (DC05535, KCD). 

56 


INTER- AND INTRA-SPECIES ANTENNAL IMAGINAL DISC 

TRANSPLANTS: BEHAVIOR, SENSORY AND CENTRAL 

OLFACTORY NEUROPHYSIOLOGY 

Hillier K.N. 1, Vickers N.J. 1, Linn C. 2 1Biology, University of Utah, Salt 

Lake City, UT; 2Entomology, Cornell University, Geneva, NY 

Vertebrate and invertebrate organisms share a common feature in 

having the primary olfactory neuropil organized into discrete knots 

known as glomeruli. The macroglomerular complex (MGC) is a 

sexually dimorphic cluster of male-specific, pheromone-receptive 

glomeruli that is configured differently between moth species. The 

physiology and arrangement of MGC glomeruli is dictated, in part, by 

the antennal imaginal disc. We have previously demonstrated that premetamorphic 

inter-species transplantation of antennal imaginal discs 

resulted in the development of a 'donor' type MGC. Our current study 

seeks to gain further insight into the factors affecting changes in 

olfactory physiology and behavior through unilateral transplantation of: 

a) a Heliothis virescens disc into Helicoverpa zea (V-Zr), and b) a H. 

virescens disc into a H. virescens recipient (V-Vr). To test moth 

behavioral discrimination, unoperated antennae were removed and the 

ability of moths to differentiate between each species' pheromone 

blends was tested in a wind tunnel. Both transplant types had similar, 

unusual sensory neurons tuned to Z9-16:Ald, an essential component of 

the normal H. zea pheromone blend. However, only V-Zr males 

responded behaviorally to blends containing this compound. Cobaltlysine 

stains of the sensilla housing these unexpected sensory neurons 

and recordings from central interneurons suggested that this behavioral 

difference was the result of the specific MGC glomeruli activated by 

this compound. Supported by NIH-1 R55 DC04443-01 to CEL 


MACROGLOMERULI IN THE WORKER CASTE OF LEAF- 

CUTTING ANTS 

Kleineidam C.J. 1, Obermayer M. 1, Halbich W. 1, Roessler W. 1 

1University of Wuerzburg, Wuerzburg, Germany 

Workers of leaf-cutting ants express an extraordinary size 

polymorphism with a factor of 1000 in body mass. Foraging workers 

show less variation but still can be discriminated in minor and medium 

workers. We asked the question whether these workers differ in a) their 

morphology of the first olfactory neuropil, the antennal lobe, b) their 

olfactorial behavior to trail pheromones and c) their receptor neuron 

response to trail pheromones. We found, for the first time in nonsexual 

individuals, a greatly enlarged glomerulus. The comparison of two 

closely related species Atta sexdens and Atta vollenweideri by 3Dreconstructions 

of the antennal lobes revealed striking similarities as 

well as very distinct differences in the arrangement of macroglomeruli 

among the two species. Size polymorphism is found in antennal lobe 

structures, the glomeruli. While medium workers have a 

macroglomerulus, the glomeruli of the minor workers are all of similar 

size. We tested the antenna in EAGs with two common and main 

components of the trail pheromone of leaf-cutting ants (4-Methylpyrrol- 

2-Carboxylat and 2-Ethyl-3,5-Dimethylpyrazine) and found that the 

relative response to those two components differs significantly. If a 

larger glomerulus reflects a larger number of terminating receptor 

neurons, this result supports the idea that the macroglomerulus is 

involved in trail detection. In behavioral tests we found that trail 

following behavior is somewhat lower in minor workers than in 

medium workers. Surprisingly, in a choice experiment with gland 

extracts of nestmates and of the comparison species the minor workers 

outperformed the medium workers. Funding: DFG; SFB 554


THE EFFECTS OF STIMULUS DYNAMICS ON OLFACTORY 

LOBE RESPONSES IN THE CRAYFISH, PROCAMBARUS 

CLARKII USING ENSEMBLE RECORDING TECHNIQUES 

Wolf M. 1, Daly K. 2, Moore P.A. 1 1Biological Sciences, Bowling Green 

State University, Bowling Green, OH; 2Entomology, Ohio State 


Two major issues facing sensory ecologists are how olfactory 

information is coded in the nervous system and that information 

correlates with behavior. Behavioral results from our lab indicate that 

crayfish are sensitive and respond to temporal components of an odor 

signal. As such, we expect to find that underlying this sensitivity to 

stimulus dynamics, are neural correlates evident within the olfactory 

system. Thus, in this preliminary study, we investigated how the 

temporal aspects of an odor signal are coded in the olfactory lobe of the 

crayfish. Neural ensemble recordings were made on an isolated head 

preparation perfused with oxygenated crayfish saline. Silicon 

multichannel electrode arrays were inserted into the olfactory lobe of 

the crayfish brain. The medial antennule was placed into an 

olfactometer and stimulated with 3 types of stimuli; glutamate, glycine, 

and shrimp extract. The stimuli were presented at a specific molar 

concentration (10-5 M) and duration (500 ms), varying only the 

intermittency between odor pulses. Our results suggest that coordinated 

clusters of units, which collectively produced odor-dependent responses 

but these responses were further dependent on stimulus intermittency. 

These results are consistent with our behavioral data demonstrating that 

crayfish are sensitive to the manner in which odors are experienced. 

This work was supported by the McDonnell Foundation (KCD), 

NIDCD-DC05535, KCD and a Sigma Xi Grant-in-aid of research 

(MCW) 

57 


THE EFFECT OF STIMULUS DURATION ON EUCLIDIAN 

RESPONSE DISTANCE MEASURES OF ODOR 

DISCRIMINATION ACROSS ANTENNAL LOBE 

POPULATIONS IN MANDUCA SEXTA. 

Daly K.C. 1, Smith B.H. 1 1Entomology, Ohio State University, 

Columbus, OH 

Behavioral studies suggest that animals such as the moth Manduca 

sexta perceive subtle differences between odorant based on changes 

molecular features such a carbon chain length. Recent theories of 

temporal coding predict that closely related odors are “decomposed” 

over time and that longer duration stimulations should provide 

additional information used by the antennal lobe (AL) or olfactory bulb 

to enhance discrimination. To test this we measured the degree to which 

AL ensembles could statistically discriminate closely related odors as a 

function of increasing stimulus duration. Multiunit recordings from 

moths ALs were analyzed in response to 6 alcohols and ketones that 

were repeatedly presented at odor pulse durations ranging from 50 to 

4000 ms. Principle Components Analysis, on binned data (10ms), 

extracted orthogonal factors each representing a collection of units with 

common and coordinated responses. General Linear Modeling 

identified factors with odor-dependent temporal effects (p< 0.001). 

Odor-dependent factors were treated as independent dimensions and the 

Euclidian distance between odor responses at bin was calculated in a 

high dimensional space. We find that population trajectories rapidly 

peak (animal specific ~120-240 ms) and does so at the same time 

irrespective of stimulus duration. For longer durations, trajectories do 

tend to stay separated for the duration of the pulse length. These 

preliminary results suggest that olfactory systems have the capacity to 

represent odorant identity of subtly different odors rapidly. Supported 

by NIH-NCRR; RR14166-06 (BS) & NIH-NIDCD; DC05535-01 and 

the McDonnell Foundation (KD) 


CHARACTERIZATION OF LABELED CELLS IN THE 

OLFACTORY BULB OF TRANSGENIC ZEBRAFISH 

EXPRESSING THE SIMIAN CYTOMEGALOVIRUS (SCMV) 

PROMOTER 

Fuller C.L. 1, Suhr S.T. 2, Goldman D.J. 2, Byrd C.A. 1 1Biological 

Sciences, Western Michigan University, Kalamazoo, MI; 2Mental 

Health Research Institute, University of Michigan, Ann Arbor, MI 

The CMV promoter is commonly used for the production of 

transgenic animals due to its effective and essentially ubiquitous 

expression. We used a simian CMV promoter to drive the expression of 

a fluorescent reporter protein, dsRed, in zebrafish. Expression of the 

sCMV promoter has been confirmed in several regions throughout the 

nervous system including a specific subset of cells in the olfactory bulb. 

These olfactory bulb cells were among the first to express the transgene 

early in development. The purpose of this study was to examine the 

morphology, distribution, and identity of the labeled cells in the 

olfactory bulb using confocal microscopy, immunocytochemistry, and 

retrograde tract-tracing methods. The labeled cells have teardropshaped 

somata that are 5-10 microns in diameter. The cell bodies are 

found throughout the glomerular and superficial internal cell layers, and 

they possess a single prominent process containing tufts in the 

glomerular layer. Although these cells are found in the same location as 

mitral cells, they do not appear to be output neurons since retrograde 

labeling of the olfactory tracts with a fluorescent dextran identifies a 

different subset of bulbar cells. We are continuing our exploration of 

the identity of the bulbar neurons that are labeled in these transgenic 

zebrafish. 

Supported by NIH DC04262 (CAB) and a grant from the Hereditary 

Disease Foundation: Cure Huntington´s Disease Initiative (STS).


CADHERIN AND CATENIN EXPRESSION IN THE 

OLFACTORY NERVE 

Akins M. 1, Greer C.A. 2 1Neurosurgery, Yale University, New Haven, 

CT; 2Neurobiology, Yale University, New Haven, CT 

Olfactory sensory neurons extend axons to the olfactory bulb, where 

they form the olfactory nerve layer (ONL), which is subdivided into 

outer (ONLo) and inner (ONLi) sublaminae. In the ONLo axons 

primarily undergo extension and gross targeting while targeting specific 

glomeruli occurs within the ONLi. Mechanisms for differential axoaxonal 

adhesion within the ONLi versus the ONLo are not known. 

However, the cadherin family of molecules are candidates. Together 

with their intracellular binding partners, the catenins, they mediate 

homotypic cell-cell adhesion and have been implicated in many roles 

during neural development, including axonal extension and specific 

circuit formation. Using immunohistochemistry, we have localized Ncadherin 

(CDH2) and several catenins in the mouse olfactory pathway. 

CDH2 and several catenins are more strongly expressed in the ONLo 

than the ONLi during perinatal development, a pattern that is absent in 

adulthood. γ-Catenin, which binds directly to cadherins and links to the 

cytoskeleton, is expressed strongly in the ONLo, as is δ-catenin, which 

binds directly to cadherins and modulates their function. In contrast βcatenin, 

which competes with γ-catenin for cadherin binding, is 

expressed uniformly in the ONLo and ONLi, as is p120-catenin, which 

competes with δ-catenin. These findings suggest the presence of two 

different cadherin-based adhesion systems in the ONL, one of which 

contains CDH2, γ-catenin, and δ-catenin and helps restrict axons to the 

ONLo during extension. Preliminary evidence further suggests that 

intermediate filaments may be involved in the function of this adhesion 

system. 

DC006335, DC00210 


ACTION POTENTIAL BACKPROPAGATION AND MODULAR 

PROCESSING OF VOMERONASAL RECEPTOR INPUT IN 

RAT ACCESSORY OLFACTORY BULB 

Ma J. 1, Lowe G. 1 1Monell Chemical Senses Center, Philadelphia, PA 

In main olfactory bulb, receptor cells expressing one OR gene project 

to unique paired glomeruli. Mitral cells link to single glomeruli via 

simple primary dendrites which reliably propagate action potentials. 

Accessory olfactory bulb (AOB) exhibits more complex wiring: 

sensory neurons (VSNs) expressing one VR gene make divergent 

projections to many glomeruli, and mitral cells link to multiple 

glomeruli via branched primary dendrites. We applied Ca-imaging to 

track backpropagating action potentials (BPAPs) in rat AOB primary 

dendrites. Under whole-cell dialysis with 100 µM Ca-orange, somatic 

spike-evoked fluorescent signals were detected over the entire dendritic 

tree; ∆F/F was nearly constant on all branches from soma to glomeruli. 

Backpropagation relied on Na + channels: in 1 µM TTX, somatic AP 

voltage-clamp commands evoked dendritic Ca-transients that declined 

significantly with distance compared to current-clamp controls. Dual 

soma-dendrite recording confirmed that BPAPs were unattenuated, 

while subthreshold voltage transients declined markedly. Ca-transients 

were not significantly altered by 100 µM APV or 50 µM bicuculline, 

suggesting BPAPs are unaffected by local synaptic input. Genetic 

tracing in AOB has suggested homotypic connectivity - individual 

dendritic arbors project only to glomeruli targeted by VSNs expressing 

the same VR gene. Non-decremental, non-dichotomous 

backpropagation in AOB primary dendrites ensures fast, reliable 

communication between mitral cells and their homotypic glomeruli, 

binding them into coherent modules in accordance with their VR-coded 

inputs. Supported by NIDCD DC04208 (GL). 

58 


MITRAL/TUFTED AND GRANULE CELL RESPONSE 

SPECIFICITY IN THE MOUSE OLFACTORY BULB. 

Davison I.G. 1, Shtoyerman E. 1, Katz L.C. 1 1Dept. of Neurobiology, 

Duke University Medical Center, Durham, NC 

Odor representations passed from the olfactory bulb to higher brain 

centers are contained in the firing patterns of olfactory bulb 

mitral/tufted (M/T) neurons. The degree of stimulus specificity of M/T 

neurons has important implications for distinguishing between 

competing hypotheses of olfactory coding. Assessing stimulus 

specificity has been difficult due to the huge size of òdor space´: the 

range of potentially active volatile chemicals that could activate a 

neuron. To examine M/T response specificity, we use a computercontrolled, 

robotic odor delivery system that allows fast and simple 

application of hundreds of odorants with precisely controlled dilution 

and timing. Extracellular single unit recordings from the mouse OB in 

vivo, using odorant concentrations within a behaviorally relevant range, 

revealed that M/T responses are extremely specific. When presented 

with a large panel of structurally diverse and closely related categories, 

M/T neurons typically respond to


ONTOGENY OF ODOR DISCRIMINATION 

Fletcher M. 1, Wilson D. 1 1Zoology, University of Oklahoma, Norman, 

OK 

Individual olfactory bulb mitral/tufted cells respond preferentially to 

groups of molecularly similar odorants. Bulbar interneurons are 

thought to influence mitral/tufted odorant receptive fields (RFs) through 

mechanisms such as lateral inhibition. Infant rats, however, lack a 

majority of these inhibitory interneurons until the second week of life. 

It is unclear if these developmental differences affect mitral/tufted RFs 

or affect behavioral odor discrimination. The following experiments 

aimed at better understanding olfactory bulb mitral/tufted cell receptive 

fields, odor coding, and behavioral odor discrimination in the 

developing olfactory system. 

Single-unit and local field potential recordings were made from 

mitral/tufted cells of freely breathing urethane-anesthetized rats (PN4 – 

adult). RFs to a homologous series of esters of different carbon chain 

lengths were mapped for each age group. Odorants were equated for 

concentration (150 PPM) using a flow dilution olfactometer. 

Preliminary results suggest minimal differences between infant and 

adult single-unit mitral/tufted RFs. However, odor-evoked local field 

potential oscillations showed a strong age-dependent change in 

dominant frequency over the age range tested. Behavioral odor 

discrimination to the same set of odorants is currently being examined 

using our cardiac orienting response paradigm, which is effective even 

in very young (PN4) animals. 

Supported by: DC03906 to DAW and F31 DC006126 to MLF 


EFFECTS OF FUNCTIONAL GROUP POSITION ON 

GLOMERULAR ACTIVATION PATTERNS EVOKED BY 

ESTER AND ALCOHOL ODORANTS. 

Johnson B.A. 1, Leon M. 1 1Neurobiology and Behavior, University of 

California, Irvine, Irvine, CA 

Studies of the relationship between odorant structure and bulbar 

activity patterns have identified glomerular modules that recognize 

discrete odorant molecular features such as functional groups. In the 

present experiments, we asked if the position of functional groups 

within odorants influences spatial activity patterns. By mapping uptake 

of [14C]2-deoxyglucose across the entire glomerular layer, we 

compared the influences of functional group position and carbon 

number using systematically differing series of 21 alcohols and 16 

esters. Along every carbon number and positional series, 

representations were chemotopic, with the most similar chemicals 

evoking the most similar patterns. However, the relative impact of the 

position of the functional group differed greatly for esters and alcohols. 

Changing the position of the ester functional group determined whether 

or not particular glomerular modules were activated, but caused only 

small differences in the overall glomerular activity pattern. In contrast, 

changing the position of the alcohol functional group evoked very 

distinct patterns involving entirely different groups of glomerular 

modules. Thus, the position of functional groups is an important feature 

determining patterns of glomerular activity, although the nature of the 

difference in the evoked response depends on the functional group. 

Supported by grant DC03545. 

59 


RESPONSES TO KETONES ARE NOT ORGANIZED 

CHEMOTOPICALLY WITHIN A KETONE-RESPONSIVE 

GLOMERULAR MODULE. 

Farahbod H. 1, Johnson B.A. 1, Leon M. 1 1Neurobiology and Behavior, 

University of California, Irvine, Irvine, CA 

We have shown previously that every odorant activates a unique 

combination of glomerular modules in the rat olfactory bulb. Some of 

the modules appear to respond to a range of odorant molecules sharing 

a chemical feature such as a functional group. Within modules 

responding to aldehydes, alcohols, and acids, responses are arranged 

chemotopically with respect to molecular length. Ketones activate a 

module located dorsomedially in the bulb and in the present study, we 

investigated the possibility of a chemotopic organization within this 

module. We mapped uptake of radiolabeled 2-deoxyglucose in the 

olfactory bulbs of rats during stimulation by straight-chain ketone 

odorants that differed systematically in their carbon numbers (2pentanone 

to 2-undecanone) or in the position of their carbonyl group 

(2- and 3-hexanone and 2-, 3-, and 4-heptanone). As the carbon number 

increased, the pattern of activity in the posteriolateral, and medial parts 

of the bulb shifted toward ventral positions. However, unlike the 

responses of other functional groups, there was no change in the 

location of the responses within the ketone-responsive module as 

carbon number increased. Changing the position of other functional 

groups has been shown to affect odorant response patterns, but such 

changes were not seen within the ketone-responsive module. These data 

indicate that the organization of responses within the olfactory system 

differs across odorant functional groups. Supported by grant DC03545. 


INFORMATICS TOOLS FOR GLOBAL MAPPING OF ODOR- 

INDUCED NEURAL ACTIVITY IN THE GLOMERULAR 

LAYER OF THE RODENT OLFACTORY BULB 

Liu N. 1, Xu F. 2, Shepherd G.M. 2, Miller P.L. 1 1Center for Medical 

Informatics, Yale University, New Haven, CT; 2Neurobiology, Yale 

University, New Haven, CT 

Aims: We are developing computer software tools, OdorMapBuilder 

and OdorMapComparer, to generate and analyze odor maps in the 

rodent olfactory system. Methods: The software programs are written in 

the Java programming language. OdorMapBuilder allows users to trace 

the glomerular layer in a MRI slab, which then serves as a template for 

the glomerular fMRI density slab. The patterns from all slabs are 

combined into a 2D map image. Each position in the odor map 

represents a unique site in the OB glomerular layer, with its optical 

density representing the neural activity. To aid in analyzing the maps, 

OdorMapComparer allows users to import two maps onto a framed 

canvas, perform warping, and carry out simple addition, subtraction and 

statistical analysis between the two images. Results: The programs 

provide a user-friendly interface with a rich set of menus. 

OdorMapBuilder generates odor maps in different perspectives: dorsal, 

lateral, ventral and medial. The map images can be saved in JPEG and 

GIF format or exported as raw pixel data. OdorMapComparer enables 

quantitative comparisons of two images and calculations of the 

difference or additive effects of any two odor maps. Conclusions: The 

present study illustrates the critical role of informatics tools in 

analyzing the neural basis of the olfactory processing. In addition to 

fMRI data, these tools also apply to 3D data obtained using other 

methods. Acknowledgments: Supported by the Human Brain Project 

and the National Library of Medicine.


LATERAL INHIBITION: IT MAKES SCENTS AS A 

NEURONAL CODING STRATEGY IN OLFACTION 

Lei H. 1, Reisenman C. 1, Christensen T.A. 1, Hildebrand J.G. 1 1ARL Div. 

of Neurobiology, University of Arizona, Tucson, AZ 

There is good evidence that the primary representation of an 

olfactory stimulus is shaped by inhibitory interactions between 

glomeruli, but there are few olfactory systems in which the odor-tuning 

properties of identifiable and accessible glomeruli are known. The moth 

antennal lobe contains a small number of sexually dimorphic glomeruli: 

the macroglomerular complex (MGC) in males and the large female 

glomeruli (LFGs) in females, and evidence is increasing that the MGC, 

LFGs, and the remaining glomeruli share similar principles of synaptic 

organization. To test this idea further, we used intracellular recording 

and staining to examine the odor-evoked responses of projection 

neurons (PNs) innervating spatially identifiable glomeruli in both sexes. 

In males, our earlier results showed that the synchronous firing of PNs 

innervating one MGC glomerulus is modulated by local inhibition from 

the neighboring glomerulus. Similarly, in females, we found that PNs 

innervating one identifiable glomerulus (G40) were depolarized 

selectively by cis-3-hexenyl acetate, while PNs innervating the lateral 

LFG (which neighbors G40) were activated selectively by (+)linalool. 

In contrast, (±)linalool evoked a rapid inhibitory potential in PNs 

innervating the adjacent G40 glomerulus. Similarly, (+) but not (-) 

linalool also evoked an IPSP in medial LFG-PNs. These results provide 

direct evidence for odor-mediated, lateral inhibitory interactions 

between glomeruli in both the pheromonal and non-pheromonal 

olfactory subsystems in this insect. Pharmacological tests that 

selectively influence GABAergic transmission are expected to shed 

light on the neurochemical basis for these inhibitory synaptic 

interactions. 

Supported by grants from the NIH/NIDCD 


CONFIGURATIONAL AND ELEMENTAL ODOR MIXTURE 

PERCEPTION CAN ARISE FROM LOCAL INHIBITION 

Cleland T. 1, Linster C. 1 1Cornell University*, Ithaca, NY 

Contrast enhancement via lateral inhibitory circuits is a common 

mechanism in sensory systems. We here employ a computational model 

to show that, in addition to shaping experimentally observed molecular 

receptive fields in the olfactory bulb, functionally lateral inhibitory 

circuits can also mediate the elemental and configurational properties of 

odor mixture perception. To the extent that odor perception can be 

predicted by slow-timescale neural activation patterns in the olfactory 

bulb, and to the extent that interglomerular inhibitory projections map 

onto a space of odorant similarity, the model shows that these inhibitory 

processes in the olfactory bulb suffice to generate the behaviorally 

observed inverse relationship between two odorants´ perceptual 

similarities and the perceptual similarities between either of these same 

odorants and their binary mixture. 

60 

232 Slide [ ] Olfactory Bulb: Coding 

HIGH-DIMENSIONAL CONTRAST ENHANCEMENT IN 

ODOR SPACE 

Cleland T.A. 1, Sethupathy P. 1 1Neurobiology & Behavior, Cornell 

University*, Ithaca, NY 

The topographical mapping of external stimulus spaces is a common 

principle of neural organization, and contributes to sensory input 

processing by facilitating contrast enhancement mechanisms such as 

center-surround lateral inhibition. This process requires that the 

intrinsic topology of the contrast enhancement mechanism match the 

underlying topology of the sensory space upon which it acts. For 

example, the spatial contrast of retinal images is enhanced by lateral 

inhibitory projections along the two dimensions of the retinal field, and 

auditory frequency tuning in the inferior colliculus is similarly 

sharpened by lateral inhibition along the single dimension of frequency 

space. 

Contrast enhancement in the olfactory system is believed to 

sharpen odor quality representations, which map onto an indeterminate 

but certainly high-dimensional sensory space. This high-dimensional 

odor space must map onto functionally two-dimensional neural cortices 

while retaining unambiguous high-dimensional similarity relationships 

that are common among conspecifics; hence, physical proximity cannot 

reliably connote stimulus similarity. For a "lateral-inhibitory" 

mechanism of contrast enhancement to function, bulbar activation by a 

given odorant feature must specifically inhibit numerous other bulbar 

regions activated by chemically similar odorant features and sparsely 

distributed in space; current models have not addressed the scope of this 

fundamentally high-dimensional problem. We here propose and 

demonstrate a novel bulbar mechanism for such hyperlateral inhibition 

in odor similarity space, and challenge this model with evidence from 

the experimental literature. 


GLOMERULAR ON-OFF MODEL OF OLFACTORY CODING 

Rinberg D. 1, Gelperin A. 1, Koulakov A. 2 1Monell chemical Senses 

Center, Philadelphia, PA; 2Cold Spring Harbor Laboratory, Cold 

Spring Harbor, NY 

We present a model for olfactory coding based on spatial 

representation of glomerular responses. In this model distinct odorants 

activate specific subsets of glomeruli, dependent upon the odorant´s 

concentration. The glomerular response specificities are understood 

statistically, based on experimentally measured distributions of odor 

detection thresholds. A simple version of the model, in which 

glomerular responses are binary (the on-off model), allows us to 

quantitatively account for the following results of human/rodent 

psychophysics: 1) just noticeable differences in perceived concentration 

of a single odor (Weber ratios) are dC/C ~ 0.1; 2) the number of 

simultaneously perceived odors can be as high as 12 (Jinks & Laing, 

1999); 3) extensive lesions of the olfactory bulb do not lead to 

significant changes in detection or discrimination thresholds. A more 

detailed model allows us to reproduce closely the conditional 

probabilities obtained in human psychophysical experiments on 

perception of complex odors.

234 Poster [ ] Social Odors and Behavior 

UNDERSTANDING CHEMICAL COMMUNICATION UNDER 

LOTIC AND LENTIC CONDITIONS IN THE LABORATORY 

WITH CRAYFISH 

Redman C. 1, Bergman D.A. 1, Moore P.A. 1 1Biological Sciences, 

Bowling Green State University, Bowling Green, OH 

The physics of environments can structure how animals send and 

receive signals. In fact, habitat specific physics may constrain signal 

transmission and provide a mechanism for evolutionary sensory biases. 

This experiment investigates how the use of chemical (olfactory) 

signals to convey social signals is influenced by environmental physics. 

If environments can place constraints upon chemical communication, 

then we would predict that crayfish found in lotic (flowing water) 

systems should be adapted for more effective communication within 

this environment and crayfish in lentic (low or no flow) systems should 

be adapted for effective communication in this environment. This 

hypothesis extends the “Matched Filter” idea of Wehner to the level of 

behavior. We hypothesize that crayfish are influenced by the 

environment, thus dominant crayfish collected from lotic systems will 

take residence upstream in the flow, whereas under lentic (no flow) 

conditions the position of dominant individuals will be random. Lotic 

conditions consisted of two flow regimes (5 cm/s and 10 cm/s) and 

lentic conditions had no flow (0 cm/s). A second experiment 

demonstrated when urine was released under these conditions. The 

crayfish received an injection of 0.1% sodium Fluorescein at a dose of 

2-6 ug g-1 body mass. The Fluorescein injection results in the 

visualization of urine released during the course of an agonistic bout. 

This section of the study examined the ability to project urine in the 

different flow regimes. This study is a model for elucidating how 

environments structure communication systems and also whether 

crayfish release urine in manner that suggests that the signal is 

deliberately released to communicate status. 


HPLC ANALYSIS OF THE CHEMICAL COMPOSITION OF 

URINE IN THE CRAYFISH, ORCONECTES RUSTICUS 

Martin A. 1, Bergman D. 1, Moore P.A. 1 1Biological Sciences, Bowling 

Green State University, Bowling Green, OH 

Social communication is important for the formation of social 

hierarchies in crayfish. Communication uses various sensory modalities 

that play a role in establishing these relationships. In crayfish, 

chemoreception has been found to play an important role in the 

development and maintenance of social hierarchies. During an agonistic 

bout, urine is released from the nephropores and is propelled in the 

anterior direction toward a conspecific by use of the fan organs 

(maxillae and maxillipeds). Conspecifics detect chemical signals with 

two pairs of antennules. Previous work has been done on the frequency 

and duration of urine releases during agonistic bouts between crayfish. 

The results show that dominant crayfish have a longer duration and 

more frequent release of urine than subordinates. However, there may 

also be differences in the chemical composition of urine in dominant 

and subordinate animals, perhaps due to intrinsic variability. This 

project used HPLC to examine the different chemical components 

present within the urine of dominant and subordinate individuals. The 

social status and previous social experience of crayfish altered the 

presence or absence of chemical cues within the urine. In addition, the 

quantity of urine released differed between dominant and subordinate 

crayfish. Therefore, social status alters the composition of chemicals 

within urine. Consequently, it appears as if crayfish can alter the 

behavior of conspecifics by releasing urine during a fight, and that this 

urine may be a true indicator of social status and fighting ability. 

61 


THE UTILIZATION OF THE MAJOR CHELAE BY MALE 

CRAYFISH (ORCONECTES RUSTICUS) FOR DETECTING 

FEMALE PHEROMONES 

Belanger R.M. 1, Moore P.A. 1 1J.P. Scott Center for Neuroscience, 

Mind & Behavior, Bowling Green State University, Bowling Green, OH 

The abundance and spatial distribution of the sensory hairs of the 

major chelae of the crayfish (Orconectes rusticus) are dependent upon 

the sex and reproductive form of the crayfish. It has been previously 

demonstrated that the major chelae may have chemosensory abilities 

that function to detect pheromones or mating signals. Given these 

previous results, we determined if form I (reproductive) male crayfish 

use their major chelae to detect potential female pheromones in order to 

locate potential mates. This study provides a link between the previous 

morphological studies and reproductive behavior. We videotaped and 

analyzed the behavioral reactions of form I males (N=20) to female 

conditioned water (N=6), male conditioned water (N=6), and control 

water. Following this, we used males that had their chelae sensory 

deprived (lesioned) by coating them with super glue. We found that 

unlesioned form I males responded significantly more (P = 0.02) to 

female odor than males with lesioned chelae (P = 0.61). These results 

clearly show that the major chelae serve a chemosensory function that 

is related to distinguishing sex in crayfish. It may be possible that the 

chelae also play a chemosensory role in mate localization and courtship 

behavior. 


INDIVIDUAL RECOGNITION IN THE LOBSTER, HOMARUS 

AMERICANUS: THE LOSER REMEMBERS 

Steinbach M.A. 1, Atema J. 1 1Biology, Boston University, Woods Hole, 

MA 

Lobsters can distinguish conspecifics individually by odor, and use 

this information, carried in the urine, to establish their social structure 

through a series of agonistic encounters. In the first encounter, 

unfamiliar lobsters learn the individual odortype of their opponents. In 

second and subsequent encounters, they do not engage in highly 

aggressive interactions. In this study, we questioned which of an 

agonistic pair makes the decision not to fight a second time. We paired 

male lobsters in two successive boxing matches. Before the second 

fight, we disabled the critical antennular chemoreceptors of either the 

winner or the loser of fight one. The effects of the lesion on the 

behavior of both animals as well as the overall characteristics of the 

fight were recorded. Results show that when the subordinate´s 

chemoreceptors are disabled and the dominant remains intact, all 

behaviors and fight characteristics remain largely the same in fight two 

as in fight one. In two cases, the lesioned loser of fight one beat his 

dominant in fight two, thus overturning their dominance relationship. 

When the winner´s nose is disabled and the loser remains intact, 

however, the duration of the fight and all other measures of aggression 

decrease significantly for both winner and loser. These findings 

confirm that the loser of a fight determines the intensity of subsequent 

fights, fleeing significantly sooner and more often, thereby eliciting less 

aggression from the winner.


CHEMICAL SIGNALS AND CHEMOSENSORY PATHWAYS 

INVOLVED IN SPINY LOBSTER SHELTERING BEHAVIOR 

Horner A.J. 1, Nickles S.P. 1, Derby C.D. 1 1Biology, Georgia State 

University, Atlanta, GA 

The chemosensory system of the Caribbean spiny lobster (Panulirus 

argus) is organized into two parallel pathways that originate in different 

populations of antennular sensilla and project to specific neuropils in 

the brain. Although unique roles for each pathway in olfactory mediated 

behaviors have not been described in lobsters, work on other 

crustaceans suggests that the pathways may have different roles in the 

detection of intraspecific signals. Caribbean spiny lobsters are 

gregarious animals that often shelter together in communal dens. 

Several previous studies have demonstrated that this aggregation 

behavior is mediated by chemical signals released from sheltering 

conspecifics. However, the nature of the aggregation signal and the 

chemosensory pathways involved in its detection are currently 

unknown. We developed a shelter choice assay in a large seawater 

flume and examined the sheltering behavior of lobsters in response to a 

range of odorants including diluted conspecific urine (pheromone) and 

its chemical fractions, shrimp extract (food), and octopus odor 

(predator). Lobsters sheltered preferentially with diluted conspecific 

urine, showed no preference for the shrimp odor and avoided shelters 

with octopus odor. Thus sheltering behavior is specific to conspecific 

odors, and the aggregation signal is contained within urine. At present 

we are attempting to chemically characterize the aggregation 

pheromone, and we are also examining the importance of each of the 

chemosensory pathways in this behavior through selective ablation of 

different populations of antennular sensilla. Supported by NSF IBN- 

0077474 


IN SEARCH OF SEX PHEROMONES IN BLUE CRABS 

Kamio M. 1, Kubanek J. 2, Derby C.D. 1 1Biology, Georgia State 

University, Atlanta, GA; 2Biology, Georgia Institute of Technology, 

Atlanta, GA 

Blue crab Callinectes sapidus premolt females release a sex 

pheromone in their urine. Males detect this pheromone using antennular 

sensors, resulting in mating behaviors that include precopulatory 

display (rhythmic waving of swimming legs) and grabbing and 

guarding the female. Male crab also releases a sex pheromone that 

attracts premolt females (R.A Gleeson in Crustacean Sexual Biology, 

Columbia Univ. Press, 1991). The molecular identity of these 

pheromones remains unknown. The goal of our study is to identify 

these molecules using bioassay guided fractionation and analysis of 

differences in the composition of male and female urine. We collected 

female and male urine and separated them by ultrafiltration into three 

molecular weight fractions: 1000 Da (large). Small and middle fractions of female urine 

induced male precopulatory display as well as standing high on legs, 

spreading chelae, and grasping. These same size fractions of male urine 

induced males to perform all of these behaviors except precopulatory 

display. These results indicate that female urine contains a sex-specific 

pheromone, and male crab urine contains other chemicals such as 

species- or male-specific odors that stimulate agonistic behavior in 

other males, or even non-specific odors. Our results also show that the 

sex pheromone is either a single molecule ca. 500 Da or mixture of 

molecules including some


NEW INSIGHTS ON THE SOCIAL STRUCTURE AND ODOR 

FUNCTION OF A TANGERINE-SCENTED SEABIRD 

Kett L. 1, Hagelin J. 1, Rasmussen L. 2 1Department of Biology, 

Swarthmore College, Swarthmore, PA; 2Biochemistry and Molecular 

Biology, Oregon Graduate Institute, Beaverton, OR 

The crested auklet (Aethia cristatella ) is an arctic seabird that emits 

a tangerine-scented odor during breeding (Hagelin et al., 2003). Birds 

rub their beaks in the scented nape of a display partner, providing a 

possible mechanism for odor assessment. The exact social function of 

crested auklet odor is, as yet, unknown. Two possible hypotheses 

include: (1) odor correlates with social rank, such as dominance status, 

or (2) odor acts as a sexual ornament that attracts members of the 

opposite sex. We analyzed patterns of aggression and courtship within a 

captive population of 14 birds. We also collected chemical samples 

from both the oil gland and freshly clipped feathers. Behavioral analysis 

revealed a strong linear hierarchy within our population. Among 

females, social (dominance) rank was positively related to the degree to 

which a female associated with a mate. Birds also mated assortatively 

with respect to body size. Chemical analyses revealed that both oil 

glands and feathers contained compounds characteristic of the auklet´s 

seasonal scent (e.g. cis-4-decenal and octanal; Hagelin et al., 2003). 

From the samples of top ranking females we identified more than 25 

volatile compounds in oil gland secretions, including a variety of C -C 8 10 

acids, aldehydes and alcohols. An analysis of the relative concentration 

of specific compounds versus social rank is currently underway. Such a 

comparison promises to reveal patterns related to odor function, given 

the surprisingly linear social hierarchy of our captive population. 

Funding for our research was provided, in part, through the generous 

support of the Aquarium of the Pacific, Long Beach, California. 


BEHAVIORAL AND PHYSIOLOGICAL RESPONSES TO A 

PUTATIVE ALARM ODOR IN EUROPEAN STARLINGS 

(STURNUS VULGARIS). 

Leininger E.C. 1, Hile A. 2, Hagelin J. 1 1Biology, Swarthmore College, 

Swarthmore, PA; 2USDA/APHIS/WS/NWRC/Monell Chemical Senses 

Center, Phiadelphia, PA 

Wild European Starlings (Sturnus vulgaris) produce a pungent odor 

that is detectable to humans when birds are held in captivity. Despite 

growing evidence for chemosignals in birds, alarm odors have not been 

investigated. We tested whether fecal odor of stressed European 

Starlings produced a behavioral or physiological alarm response in nonstressed 

individuals. We videotaped focal birds (n=18) while exposed 

to one of three chemical stimuli: (1) fecal odor from a stressed 

conspecific, (2) fecal odor from an unstressed conspecific, and (3) plain 

air. Fecal samples of focal birds were also collected before and after 

exposure to each treatment, and assayed for a common stress hormone 

(corticosterone [CORT]). Analyses of gaping and breathing rate, 

common distress behaviors in birds, are currently underway. We 

detected no significant difference between the three treatments in the 

frequency of other behaviors such as hopping, (p=0.58) preening 

(p=0.93), or feather fluffing (p=0.51). With regard to physiology, 

starlings tended to exhibit less of a net increase in fecal CORT levels 

after exposure to stressed conspecific odor, compared to other chemical 

treatments (p=0.097). Such a result suggests that starlings might 

experience a physiological change after exposure to the scent of 

stressed conspecifics. Though our preliminary study failed to meet 

statistical significance, it is an intriguing first step that highlights the 

need for additional, careful study of avian chemical signals. 

Funding: HHMI Summer Research Stipend from Swarthmore 

College (EL); USDA/ APHIS/ WS, NWRC, and Monell Chemical 

Senses Center (AGH). 

63 


THE INFLUENCE OF CONTEXT ON FEMALE MHC-BASED 

MATE CHOICE 

Shaw - Taylor E.E. 1, Mcclintock M. 2 1Pyschology, University of 

Chicago, Chicago, IL; 2Institute for Mind and Biology, University of 

Chicago, Chicago, IL 

The primary function of the molecules of the major 

histocompatibility complex, the MHC, is to enable antigen presentation 

to T-cells, thereby initiating an immune response. The MHC also 

influences mating behavior such that individuals choose mates who 

express MHC alleles that are different from their own. MHC-based 

disassortative mate choice has been shown in mice, fish, and humans. 

Females more so than males may mate disassortatively with respect to 

the MHC because of potential immune and fitness benefits that this 

genetic diversity provides offspring. However, reports from some 

MHC-based odor studies, wherein females were presented with the 

odors from males possessing many different MHC alleles, did not 

indicate preferences for the most MHC differences. Rather, females 

preferred the odors of males with whom they shared a few of the same 

alleles, suggesting that the preferred MHC difference is relative to the 

female´s own MHC diversity. We previously tested this hypothesis and 

presented data consistent with preference for differences—the greater 

the MHC difference, the greater the preference. However, we also 

showed that the direction of preference depended on the type of choice 

being made—whether females were choosing between a male identical 

in MHC and one different or between two males that were both 

different in MHC, in number of alleles. To further investigate the 

influence of context, we have expanded the study with more subjects 

and another MHC haplotype. We present data that female rats (Rattus 

norvegicus) consider the context of choice, as indicated by male MHC 

differences, when making mating decisions. 

Supported by an NIMH MERIT Award to MKM and Hinds Research 

Fund. 


THE SCENT OF FRIENDSHIP: HIGH SCHOOL STUDENTS 

RESEARCH THE MYSTERIES OF HUMAN ODOR 

RECOGNITION 

Olsson S.B. 1, Barnard J. 2, Turri L. 2 1Neurobiology and Behavior, 

Cornell University, Geneva, NY; 2Biology, Geneva High School, 

Geneva, NY 

Though several studies have examined the effect of human odor on 

kin recognition and mate choice, few have focused on the impact of 

familiarity on recognition of non-relatives. As part of a program 

designed to engage students in scientific research, 55 10th grade and 

Advanced Placement biology students researched, planned, and 

implemented a project to analyze the effect of odor on human 

recognition of, and preference for, close friends, gender, and self. Each 

student and friend of their choosing wore a T-shirt for three consecutive 

nights. During that time, subjects were controlled for exposure to 

extraneous perfumes, household odors, and other humans. The students 

were then asked to smell a series of shirts and evaluate them with 

respect to pleasantness. Students were also asked to identify the two 

shirts belonging to themselves and their friend, and determine the 

gender of each shirt. Results of this testing will be presented along with 

a discussion of its implications for human social behavior. This research 

is supported by the NSF Graduate Teaching Fellows in K-12 Education 

Program and Cornell University through the Cornell Science Inquiry 

Partnerships Program.

246 Slide [ ] Olfactory Behavior & Psychophysics 

FORAGING IN A COMPLEX CHEMICAL LANDSCAPE: DOM 

FROM ELEVATED CO2 DETRITUS AND ITS IMPACT ON 

CRAYFISH ORIENTATION TO A FOOD SOURCE 

Adams J. 1, Moore P.A. 1 1Biological Sciences, Bowling Green State 

University, Bowling Green, OH 

Crayfish must locate food resources in a chemically complex 

environment where chemicals from various sources interact and mix 

with one another. We tested whether an additional chemical food source 

of leachate from detritus (dissolved organic matter, DOM) produced at 

ambient (AMB) or elevated (ELEV) atmospheric CO and presented at 

2 

two different concentrations would affect crayfish orientation behavior. 

Crayfish (Orconectes virilis) orientation was observed in a recirculating 

flume where a fish odor source was placed downstream of a DOM odor 

source. Preliminary analysis of the chemical signal demonstrated that 

the fine-scale spatiotemporal structure of the odor plume was different 

upon introduction of a background DOM odor. Behavioral treatments 

were as follows: 1) CON (Control; no DOM present), 2) AMB-Low 

(AMB DOM present at 3 mg/L), 3) AMB-High (AMB DOM present at 

6 mg/L), 4) ELEV-Low (ELEV DOM present at 3 mg/L), and 5) 

ELEV-High (ELEV DOM present at 6 mg/L). Crayfish in the AMB- 

High treatment were more successful in locating the source. In contrast, 

animals in the ELEV-High treatment had higher turning angles and 

heading angles than all other treatments. No differences were found for 

temporal parameters of orientation. Overall, these results indicate that 

crayfish orientation to a fish odor source is affected by the presence of 

DOM from detritus when it is present at the high end of a natural range 

of DOM concentration, perhaps resulting in a chemical “cocktail party” 

effect. This research was funded by the NSF/IGERT BART program 

(JAA) and NSF DAB 9874608 (PAM). 


CHEMICALLY-INDUCED ANTENNULAR GROOMING IN 

THE SPINY LOBSTER, PANULIRUS ARGUS, IS MEDIATED 

BY NON-OLFACTORY SENSILLA 

Schmidt M. 1, Derby C.D. 1 1Biology, Georgia State University, Atlanta, 

GA 

In decapod crustaceans, the 1st antennae bearing olfactory and other 

chemo-mechanosensory sensilla are groomed by mouthpart appendages 

in a stereotyped behavioral pattern. In the spiny lobster, Panulirus 

argus, antennular grooming behavior (AGB) is elicited by L-glutamate, 

and ablation experiments led to the conclusion that AGB is mediated by 

olfactory sensilla (aesthetascs) located on the lateral flagella of the 1st 

antennae (Wroblewska et al., Chem. Senses 27:769-778, 2002). The 

aim of our study was to examine this conclusion since the aesthetascs 

are closely associated with other sensilla, the asymmetric setae, which 

had also been eliminated. In two independent sets of experiments, we 

first showed that intact animals responded with AGB upon stimulation 

with 0.5 mM L-glutamate, then removed either all asymmetric setae (N 

= 8 / N = 7) or all aesthetascs (N = 8 / N = 6). Aesthetasc ablation did 

not reduce AGB, whereas ablation of asymmetric setae almost 

completely eliminated it. A 3rd set of experiments showed that 

aesthetasc ablation also has no positive effect on AGB. Electron and 

confocal microscopy suggest that asymmetric setae are bimodal chemomechanosensory 

sensilla, defined by the presence of a terminal pore 

and a scolopale. We conclude that AGB is elicited by chemosensory 

input provided by asymmetric setae and that it is not mediated by the 

olfactory pathway but by a parallel chemo- and mechanosensory 

pathway constituted by the lateral antennular neuropils (Schmidt & 

Ache, J Comp Physiol A 178:579-604, 1996). Supported by NSF (IBN- 

0077474) 

64 


DISCRIMINATION BETWEEN ENANTIOMERS OF CARVONE 

AND TERPINEN-4-OL ODORANTS IN NORMAL RATS AND 

THOSE WITH LESIONS OF THE OLFACTORY BULBS 

Slotnick B. 1, Mcbride K. 2 1Psychology, University of South Florida, 

Tampa, FL; 2Psychology, American University, washington, DC 

Rats trained on an operant conditioning task were used to assess 

whether the enantiomers of terpinen-4-ol, odorants that activate very 

similar areas of the olfactory bulb are more difficult to discriminate 

than those of carvone, odorants that activate different areas of the 

olfactory bulb, and to determine the effects of disrupting identified 

bulbar sites activated by these odorants. In psychophysical tests in 

which odor concentration was gradually reduced to near threshold 

levels, normal rats discriminated between the enantiomers of terpinen- 

4-ol and of carvone equally well. Olfactory bulb lesions that removed 

the majority of bulbar glomeruli activated by these odorants (as 

demonstrated in prior olfactory bulb studies using optical imaging and 

2-deoxyglucose) resulted in increased detection thresholds but little or 

no deficits in discriminating between supra threshold concentrations of 

the enantiomers. These results fail to confirm predictions based on 

maps of bulbar activity that enantiomers of terpinen-4-ol should be 

more difficult to discriminate than those of carvone and that the ability 

to discriminate between enantiomers of an odorant are based on 

differences in patterns of bulbar activation produced by the odorants. 


SIZE AND NUMBERS DON´T MATTER (THAT MUCH) - 

RELATIVE SIZE OF OLFACTORY BRAIN STRUCTURES AND 

NUMBER OF FUNCTIONAL OLFACTORY RECEPTOR 

GENES ARE POOR PREDICTORS OF OLFACTORY 

PERFORMANCE 

Laska M. 1 1University of Munich, Munich, Germany 

Primates are typically regarded as „microsmatic“ animals. This view, 

however, is only based on an interpretation of neuroanatomical and 

recent genetic findings and not on physiological evidence. We 

determined olfactory detection thresholds in squirrel monkeys and 

pigtail macaques for more than 40 odorants from different chemical 

classes and compared their performance to that of human subjects and 

nonprimate mammals. We found that – contrary to the traditional view - 

human subjects do not generally perform poorer than monkeys, and Old 

World primates do not generally show higher threshold values than 

New World primates. Furthermore, human and nonhuman primates 

show an olfactory sensitivity which for several substances matches or 

even is markedly better than that of species believed to be 

„macrosmatic“ such as dogs, rats, or mice. Similarly, human and 

nonhuman primates do not generally perform poorer in discriminating 

between structurally related odorants compared to nonprimate 

mammals and insects.We conclude that between-species comparisons 

of neuroanatomical features or of the number of functional olfactory 

receptor genes are poor predictors of olfactory performance. 

Differences in olfactory sensitivity and discrimination abilities within 

and between species seem to reflect evolutionary adaptations to 

ecological niches.


A PSYCHOPHYSICAL TEST OF THE VIBRATION THEORY 

OF OLFACTION 

Keller A. 1, Vosshall L.B. 1 1Laboratory of Neurogenetics and Behavior, 

Rockefeller University, New York, NY 

At present no satisfactory theory exists to explain why a given 

molecule has a particular smell. A recent book about the physiologist 

Luca Turin has generated new interest in the theory that the smell of a 

molecule is determined by its intramolecular vibrations rather than by 

its shape. We present the first psychophysical experiments in humans 

that test key predictions of this theory. The results suggest that 

molecular vibrations alone cannot explain the perceived smell of a 

chemical. Specifically, we have found that: (i) in a component 

identification task no vanilla odor character was detected in the mixture 

of benzaldehyde and guaiacol (ii) odor similarity ratings did not reveal 

that even and odd numbered aldehydes form two odor classes and (iii) 

naive subjects who could easily discriminate the smell of two molecules 

that differ in shape but not in molecular vibration failed to discriminate 

two molecules with similar shape but different molecular vibrations in 

three different experimental paradigms (similarity rating, duo-trio test, 

triangle test). Taken together our findings are consistent with the idea 

that the smell of a molecule is determined by its shape but we found no 

evidence that the smell of a molecule is influenced by its vibrational 

properties. 


FUNCTIONAL CONNECTIVITY OF THE HIPPOCAMPUS 

DURING AN OLFACTORY TASK: DIFFERENCES OBSERVED 

BETWEEN YOUNG AND ELDERLY 

Calhoun-Haney R. 1, Ferdon S. 2, Barbara C. 2, Murphy C. 2 1Clinical 

Psychology, San Diego State University, San Diego, CA; 2Psychology, 

San Diego State University, San Diego, CA 

Interest in the role of the hippocampus (HIP) for olfactory function 

has increased since the discovery that initial neuropathological changes 

indicative of Alzheimer's Disease (AD) occur in mesial temporal 

olfactory regions. The present study investigated differences in the 

functional relationship between the HIP and classic olfactory regions in 

young and elderly adults in response to odor stimulation. Activation in 

reference voxels located in left and right hippocampi were separately 

averaged and correlation coefficients between these and all other brain 

voxels were calculated. Group analyses were also performed in order to 

detect brain areas with significant differences in their strength of 

functional association to the hippocampi. For the young, both left and 

right hippocampi demonstrated strong functional associations with 

classic olfactory areas while the elderly exhibited a reduced number of 

functional associations. In addition, while both right and left 

hippocampi demonstrated functional connectivity with ipsilateral 

orbital frontal cortices in the young, functional connectivity was not 

observed between the left HIP and left orbital frontal cortex in the 

elderly. However, a notably larger area of the right orbital frontal cortex 

displayed connectivity with the right HIP, suggesting the possibility of 

a compensatory process in the elderly. Group analyses further 

demonstrated age differences in strength of functional associations 

among regions. The present study illustrates the effect of aging on 

hippocampal function and provides a foundation for further 

understanding of its dysfunction when affected by a neurodegenerative 

disease such as AD. Supported by NIH grant AG04085 to CM. 

65 


IMPACT OF THE CHEMICAL SENSES ON AUGMENTING 

MEMORY, ATTENTION, REACTION TIME, PROBLEM 

SOLVING, AND RESPONSE VARIABILITY: THE 

DIFFERENTIAL ROLE OF RETRONASAL VERSUS 

ORTHONASAL ODORANT ADMINISTRATION 

Zoladz P. 1, Raudenbush B. 1, Lilley S. 1 1Psychology, Wheeling Jesuit 

University, Wheeling, WV 

Past research has consistently noted a significant interplay between 

odors and human behavior. Multiple studies have shown that the 

administration of particular odorants can enhance athletic performance, 

sleep, pain tolerance, mood, and cognitive processing. In addition, 

odorants have a differential effect on human behavior, dependent upon 

route of administration (retronasal vs. orthonasal). The present study 

examined the differential effects of odorants administered retronasally 

and orthonasally on cognitive performance. During Phase I, 31 

participants completed cognitive tasks on a computer-based program 

(Impact®) under five "chewing gum" conditions (no gum, flavorless 

gum, peppermint gum, cinnamon gum, and cherry gum). During Phase 

II, 39 participants completed the same cognitive tasks under four 

odorant conditions (no odor, peppermint odor, jasmine odor, and 

cinnamon odor). Participants also completed pre- and post-test 

assessments of mood, and rated their perception of the required 

workload. Results revealed a task-dependent relationship between odors 

and the enhancement of cognitive processing. Cinnamon, administered 

retronasally or orthonasally, improved participants' scores on tasks 

related to attentional processes, virtual recognition memory, working 

memory, and visual-motor response speed. Implications of the present 

study are most promising in providing a non-pharmacological adjunct 

to enhancing cognition in the elderly, individuals with test-anxiety, and 

perhaps even patients with diseases that lead to cognitive decline. This 

study was funded by a grant from Psi Chi to P. Zoladz. 


THE MAGIC NUMBER 3 APPLIES TO COMPONENTS 

IDENTIFIED IN COMPLEX ODOR-TASTE MIXTURES 

Laing D. 1, Marshall K. 1, Jinks A. 1, Hutchinson I. 1 1Centre For 

Advanced Food Research, University of Western Sydney, Sydney, 

Australia 

Humans can identify up to 3 components in taste or odour mixtures 

(Laing & Francis, 1989; Laing et al., 2002), but their capacity to 

analyse multi-component odour-taste mixtures is unknown. With binary 

mixtures both components are usually perceived, however, only tastants 

were identified in 3-component mixtures containing one odorant. 

(Laing et al., 2002), suggesting taste may dominate smell in odor-taste 

mixtures. Here, the aim was to determine the number of identifiable 

components in complex odor-taste mixtures and investigate the report 

of dominance of taste over smell. 43 subjects were trained to identify 

'equi' intense aqueous solutions of the tastants sucrose, sodium choride 

and citric acid, and the odorants cinnamaldehyde (cinnamon), cis 3hexenol 

(grass-like) and 2-pentanone (like nail polish remover). Over 2 

test sessions they were asked to identify the components of 36 mixtures 

containing from 1 to 6 components presented in random order. Stimuli 

were sampled by mouth using a straw sited in a hole in the lid of a 30 

ml plastic cup. Subjects readily identified components in 1 and 2 

component stimuli, but with 3-6 component mixtures the mean number 

identified was 3. Clearly, increasing the number of modalities in a 

mixture did not increase the number of components identified. As 

reported earlier, tastes were more readily identified than odors in 

mixtures. The limit of 3 components strongly suggests the limiting 

factor is working memory, the memory that is used to rapidly identify a 

stimulus and initiate a response within a second or two.

254 Symposium [ ] Non-neuronal Cells of the Olfactory 

System in Development 

SUSTENTACULAR CELLS - MORE ACTIVE THAN WE EVER 

IMAGINED 

Hegg C. 1, Vogalis F. 1, Lucero M. 1 1Physiology, University of Utah, Salt 

Lake City, UT 

Sustentacular cells are morphologically polarized and have structural 

features that allude to functions of secretion, absorption, phagocytosis, 

maintenance of extracellular ionic gradients, metabolism of noxious 

chemicals, and regulation of cell turnover. Here, we review the well 

characterized morphology and ultrastructure of mammalian 

sustentacular cells and present data investigating their dynamic activity. 

We show, using a mouse olfactory epithelium slice model, that 

sustentacular cells have voltage-gated Na + and K + channels and are 

capable of evoking rapid, robust increases in intracellular calcium in 

response to P2Y purinergic receptor activation. In addition, 

sustentacular cells propagate waves of calcium oscillations initiated by 

either endogenous release or exogenous application of ATP or other 

putative neurotransmitters. Oscillations in intracellular calcium may 

govern secretion, proliferation and development in sustentacular cells, 

and, via calcium dependent exocytosis, may provide chemical signals to 

basal cells, neuronal precursors, or neurons. Recent discoveries of 

voltage-gated channels, receptors, and transmitter release in both 

peripheral and central glial cells suggest direct communication between 

neurons and glia. The identification of similar components in 

sustentacular cells suggests that, like their glial counterparts, they are 

capable of rapid communication between themselves and the neural 

elements of the olfactory epithelium. Funded by NIDCD DC02994 

(MTL) and DC04953 (CCH). 



A GLIA - AXON PAS DE DEUX UNDERLIES OLFACTORY 

RECEPTOR AXON SORTING. 

Oland L.A. 1 1A.R.L. Division of Neurobiology, University of Arizona, 

Tucson, AZ 

The problem: Olfactory receptor neurons expressing the same 

olfactory specificity are not topographically ordered within the receptor 

epithelium, but their axons extend to just one or a pair of glomeruli in 

the olfactory bulb. Axon sorting is thus a critical process that must 

occur somewhere along the olfactory pathway. In the moth Manduca 

sexta, sorting takes place not in the nerve layer that circumscribes the 

olfactory neuropil, but rather in a discrete region of the nerve that we 

have called the axon sorting zone. This sorting zone has three 

important features: it is densely populated by glial cells, the glial cells 

can be killed without killing neurons, and it can easily be surgically 

isolated for various in vivo and in vitro experimental manipulations. 

Recent experiments have provided clear evidence for reciprocal 

interactions between the ingrowing receptor axons and the glial cells 

that affect glial cell proliferation, axon fasciculation, and growth cone 

behavior, and also are beginning to reveal the underlying molecular 

players. 

66 



SORTING AND GLIAL-NEURONAL INTERACTIONS IN THE 

OLFACTORY NERVE LAYER 

Treloar H.B. 1, Akins M. 1, Iwema C. 1, Dodds T. 1, Greer C.A. 2 

1Neurosurgery, Yale University, New Haven, CT; 2Neurobiology, Yale 

University, New Haven, CT 

Olfactory Sensory neurons (OSNs), are generated throughout life and 

extend axons that form fascicles within the olfactory nerve (ON). As 

axons enter the olfactory nerve layer (ONL) of the olfactory bulb (OB), 

they reorganize before synapsing in glomeruli. Each OSN expresses 

one odorant receptor (OR) from a family of approx. 1000 ORs. Neurons 

expressing the same OR target specific glomeruli. Thus, OSN axons 

face unique challenges when sorting. First, axons from neurons located 

widely within the OE must identify common targets, taking varied 

trajectories and presumably using multiple guidance cues. Second, as 

neurons are continually regenerated throughout life, axons must 

navigate a complex meshwork of pre-existing axons to identify target 

glomeruli. Throughout this process the unymyelinated OSN axons 

maintain intimate contact with a unique population of glia, the olfactory 

ensheathing cells (OECs). The morphological and molecular properties 

of OECs vary along the length of the axonal projection, suggesting that 

subsets of OECs subserve different functions. In the ON and peripheral 

regions of the ONL, OECs tightly bundle OSN axons and express p75. 

However, as axons approach glomeruli and radically change their 

trajectories, the population of glia they interact with changes. The 

OECs found in this region express NPY but not p75. OSN axons also 

encounter astrocytic processes within this region which emanate 

radially into the ONL from glomeruli. It is likely that a spatiotemporal 

combination of cell surface axon-axon and axon-glia interactions 

underlie glomerular targeting in the OB. 

NIH DC005706, DC00210



LOSING THE PATH; CELL MIGRATION IN A CHANGING 

FOREBRAIN 

Demarchis S. 1, Rossi F. 2, Fasolo A. 1, Puche A.C. 3 1Dept. Human & 

Animal Biol., Univ. of Turino, Turino, ., Italy; 2Dept. Neuroscience, 

Univ. of Turino, Turino, ., Italy; 3Dept. Anatomy and Neurobiol., Univ. 

of Maryland, Baltimore, MD 

The presence of a germinal layer and the capacity to generate 

neurons, once thought restricted to the embryonic brain, persists in the 

forebrain of postnatal and adult mammals. The olfactory bulb (OB), 

unlike the cortex and other regions, continues to receive new neurons 

throughout life. Despite dramatic changes in the structure and cellular 

organization of the forebrain from embryo to adult, these newly 

generated cells still migrate from germinal regions to specific targets. In 

early embryos, the OB has a cortical-like organization with radial glia 

spanning the ventricle to pia. Radial glia are likely to provide a 

migratory scaffold for cells exiting the ventricular germinal layer and 

migrating radially. As development progresses numerous cells are 

generated from a stem cell pool located in the lateral ventricle 

subventricular zone (SVZ). SVZ-derived progenitor cells migrate into 

the OB following the rostral migratory stream (RMS) and into other 

postnatal forebrain structures along different migratory pathways. After 

birth radial glia disappear and reorganize into a series of glial tubes 

along the RMS. However, once radial glia in the bulb disappear there is 

no longer a clear radial scaffold for cells to follow when migrating 

radially. Such modifications of the non-neuronal migratory 

environment are paralleled by changes in lineage characteristics of SVZ 

progenitors. Namely, progenitors that leave the SVZ at different 

developmental times generate different types of mature OB neurons. 

Thus, cell migration in the bulb is a developmentally dynamic process 

between immature cells and different non-neuronal cellular elements at 

different times. Support: NIDCD DC05739, Compagnia di San Paolo. 

and Italian Institute for Health Project CS107.1 

258 Poster [ ] Chemical Ecology 

ORIENTATION TO TEMPORALLY AND SPATIALLY 

COMPLEX ODOR SIGNALS IN THE CRAYFISH, 

ORCONECTES RUSTICUS 

Zulandt T.J. 1, Quinn E. 2, Wolf M. 3, Moore P.A. 3 1Laboratory for 

Sensory Ecology, Bowling Green State University, Bowling Green 

Ohio, OH; 2Electrical Engineering, University of Cincinnati, 

Cincinnati, OH; 3Biological Sciences, Bowling Green State University, 

Bowling Green, OH 

Organisms in natural environments encounter complex information 

and must be able to decipher this information in order to respond 

behaviorally. This complex information can be a result of various 

aspects of the natural environment such as hydrodynamics, changing 

habitats, and conflicting or multiple odor cues. In many habitats, 

multiple odor plumes in various spatial configurations often mix and 

animals must extract relevant spatial information in order to make 

appropriate orientation decisions. In this study, we show how the spatial 

configuration of multiple odor plumes influences the orientation 

abilities of crayfish. By altering the spatial configuration of odor 

sources without altering concentration or hydrodynamics it is possible 

to understand the underlying mechanisms of orientation. In this study, 

we have quantified the hydrodynamics, chemical dynamics and animal 

behavior within the artificial stream. Our results show that the different 

spatial configuration influences the distribution of odors within our 

stream and that these odors influence the subsequent orientation 

behavior. Our work indicates that it is the fine-scale distribution of 

odors that is regulating the orientation behavior of the crayfish. 

67 


FLUID DYNAMICS AND CHEMICAL SIGNALS IN THE 

CRAYFISH WALKING LEGS 

Cook M. 1, Moore P.A. 1 1Biological Sciences, Bowling Green State 


In aquatic environments, chemical cues are important in many 

species for finding resources and locating mates. Two processes 

disperse these cues: fluid flow and molecular diffusion. Fluid flow is 

dominant in spatial scales larger than 10 mm, while molecular diffusion 

is dominant at smaller spatial scales. For animals with chemoreceptive 

capabilities, sampling the environment is critical to obtain information. 

Receptor structure morphology is responsible for changing the flow 

surrounding receptor cells by creating a boundary layer. Fluid that is in 

direct contact with the receptor surface does not flow, which is known 

as the no-slip condition. The boundary layer acts as a filter, changing 

the temporal and spatial structure of the chemical signal arriving to 

receptor cells. In this study, we will employ the technique used by 

Moore and Atema 1991 to study the fluid dynamics in the 

chemosensory chelae and walking legs of the crayfish, Orconectes 

rusticus. Our goal is to determine the function of the boundary layer 

before and after chemical information has been filtered (i.e. during 

flicking) to the receptor cells. The experiment will be conducted in a 

recirculating flow tank in which the stimulus will be delivered with a 

plastic pipette. High-speed electrochemical recordings will be made 

with BAS epsilon system. It is clear that the morphology of these 

appendages influence the structure of chemical signals arriving at 

receptor cells. These results provide insight into how crayfish perceive 

chemical signals and extract information from turbulent odor plumes. 


THE ROLE THAT BOUNDARY LAYERS AROUND CRAYFISH 

SENSORY APPENDAGES ACT AS TEMPORAL FILTERS FOR 

ODOR PLUMES 

Urban L. 1, Moore P.A. 1 1Biological Sciences, Bowling Green State 


Sensory systems have a complex task of extracting relevant 

information from the environment.The interaction between fluid flow 

and the morphology of sensory appendages acts as a physical filter and 

plays an important role in extracting information.This interaction 

determines the boundary layer structure which alters the spatial and 

temporal distribution of chemical signals arriving at the receptors. This 

study was designed to exmaine the microscale fluid and chemical 

dynamics around the sensory appendages of the crayfish, Orconectes 

rusticus. Previous research has determined the biomechanics of 

sampling behaviors of the lateral antennule of the crayfish. In this 

study, we have used these biomechanical results with an 

electrochemical technique to quantify the role that boundary layers play 

around various sensory appendages in filtering the temporal dynamics 

of odor plumes.We measured the boundary layer structure and chemical 

dynamics of sensory appendages that were mounted in a flow tank 

under known flow conditions. We utilized the BAS epsilon system with 

electrochemical microelectrodes to record and quantify chemical 

dynamics with multiple electrodes around the appendage. The 

preliminary findings indicate the majority of the chemical signal flows 

around the appendage rather then through it. Boundary layer structure 

greatly affects the spatial and temporal nature of chemical signals by 

acting as a smoothing filter for incoming signals.The exact nature of 

this physical filter depends upon the ambient flow speed and the angle 

of the sensory appendage relative to flow.This study illustrates the 

importance of form and function in chemoreception and in an 

organism's ability to detect environmental cues.

261 Slide [ ] Chemical Ecology 

FROM ODOR PLUME TO ANTENNULE: DO CRAYFISH 

ANTENNULES VARY WITH FLOW HABITAT AS PREDICTED 

TO MAXIMIZE ODOR MOLECULE CAPTURE? 

Mead K.S. 1 1Biology, Denison University, Granville, OH 

Many aquatic crustaceans use water-borne chemical cues in 

ecologically critical activities such as finding food, mates, habitat, and 

avoiding predators. These chemical cues are present as odor plumes 

consisting of fine filaments of highly concentrated odor molecules 

interspersed with the surrounding fluid. The structure of the odor 

plume, and thus how the plume is encountered by navigating animals, is 

affected by factors such as the size-scale of the bottom substrate and 

flow conditions such as the mean velocity, turbulence level, and the 

gradient of flow speed above the substratum. Several species of Ohio 

crayfish (Cambarus spp. and Orconectes spp.) were collected from a 

variety of flow habitats including still ponds and turbulent streams. 

Since odor plume structure varies according to flow habitat, crayfish 

antennules from species living in different flow environments should 

have different patterns of aesthetasc arrangements on their filaments, to 

best encounter odors in that habitat. I used Image J to measure 

structural parameters such as aesthetasc number, length and diameter, 

and the ratio of the gap between aesthetasc rows to the aesthetasc 

diameter (an indication of odor penetration into the sensor array) from 

SEMs on 3 individuals per species. As predicted from odor plume 

structure, species from high flow habitats have longer aesthetascs 

(p=0.009; rsPc=0.684) and a smaller ratio of the gap between aesthetasc 

bundles to the aesthetasc diameter (p=0.092; rsPc=0.908) than species 

from low flow habitats). Funding: Denison University Research 

Foundation. 


DO MOVEMENTS OF HONEYBEE ANTENNAE ENHANCE 

CAPTURE OF ODORANTS? 

Miller G. 1, Loudon C. 1, Smith B.H. 2 1Entomology, University of 

Kansas, Lawrence, KS; 2Entomology, Ohio State University, Columbus, 

OH 

Honeybees have numerous olfactory sensory hairs that make up their 

sensory epithelium, which is distributed along the length of the 

antennae. The antennae are shaped as tubular structures that can be 

placed in different orientations and moved with low frequency through 

air. In general, antennal sensilla increase in number from proximal to 

distal. Because of this uneven distribution of sensors and the way in 

which the shape of the antennae interacts physically with the 

environment, antennal movements have important consequences for 

odorant molecule capture and, therefore, perception. Antennal 

movements were videotaped during presentation of two odorants 

(geraniol and 1-hexanol) and a control blank. Bee responses were 

recorded both before and after being trained to associate a food reward 

with an odorant, as demonstrated by a proboscis extension response. 

The movements of the antennae were analyzed in three-dimensional 

space by digitizing the base, elbow, and distal tip of each antenna. 

Antennal movements increased in response to odorants. Antennal 

movements were not simple oscillations in a plane but were 

complicated excursions in three-dimensional space. Antennae were 

oriented in an anterior direction more noticably in response to geraniol. 

Left and right antennae are moved independently of each other. These 

increased movements will increase the volume of air sampled by the 

antennae and a potential increase in odorant capture rate from the 

moving air. 

This word was supported by an award from NIH-NCRR to BHS (9 

R01 RR14166) and from NSF to CL (IBN-9984475). 

68 


OLFACTORY-MEDIATED SEARCH BEHAVIORS OF 

MIGRATORY SEA LAMPREYS SEEKING PHEROMONE- 

LADEN SPAWNING STREAMS IN THE GREAT LAKES 

Vrieze L.A. 1, Sorensen P.W. 1 1Department of Fisheries, Wildlife and 

Conservation Biology, University of Minnesota, St. Paul, MN 

The sea lamprey (Petromyzon marinus) spends its larval life in 

streams, enters large lakes or oceans as a parasitic juvenile, and 

eventually returns to streams as an adult to reproduce. Laboratory 

studies strongly suggest that lampreys locate suitable spawning streams 

using a bile acid-related migratory pheromone released by larval 

conspecifics (see Fine & Sorensen, this symposium). This study 

examined olfactory-mediated search behaviors of lampreys as they 

searched for pheromone-laden streams emptying into Lake Huron. Both 

olfactory-occluded and untreated lampreys implanted with acoustic 

telemetry tags were tracked from a GPS-equipped boat and their 

movements related to stream water concentration (as measured by 

conductivity). Outside the apparent influence of stream water, lampreys 

(N=12) swam rapidly (1.5 km/hr) and continuously on relatively 

straight bearings (straightness index = 0.78) while performing repeated 

vertical excursions through the water column. Occluded and intact 

animals swam with different compass bearings, perhaps due to differing 

responses to lake currents/odors. Upon encountering river plumes 

(N=10), lampreys with an intact olfactory sense commenced circling 

(straightness index = 0.42). The speed and success of locating the 

stream mouth was correlated with the thoroughness of mixing of the 

stream and lake waters. These behaviors, together with responses to 

stream waters previously documented in laboratory mazes, suggest the 

use of klinotactic chemo-orientation in stream finding. Funded by the 

Great Lakes Fisheries Commission. 


CHEMICAL FRACTIONATION DEMONSTRATES THAT THE 

SEA LAMPREY MIGRATORY PHEROMONE IS COMPRISED 

OF SEVERAL BILE ACID-LIKE COMPOUNDS 

Fine J.M. 1, Sorensen P.W. 1 1Department of Fisheries, Wildlife and 

Conservation Biology, University of Minnesota, St Paul, MN 

The sea lamprey (Petromyzon marinus) starts its life in freshwater 

streams which it then leaves to parasitize lake/oceanic fishes before 

eventually re-entering streams to spawn. Laboratory and field studies 

have shown that adult lampreys locate spawning streams using a 

pheromone released by stream-resident larval lampreys (see Vrieze and 

Sorensen, this symposium). Initial biochemical characterization of this 

cue found it to contain the sulfated bile acid petromyzonol sulfate (PS) 

which adult lampreys detect at 10 -12 Molar (M). Using a combination 

of HPLC fractionation, olfactory recording, behavioral assays, and mass 

spectrometry we have recently isolated two additional compounds from 

larval holding water that have pheromonal activity. The most important 

has a molecular weight of 704, co-elutes with PS by HPLC, and is 

behaviorally attractive at concentrations below 10 -14 M, a record for 

fish. The second has a molecular weight of 590 and is less potent. In a 

two-choice preference maze, adult lampreys did not distinguish 

between larval water and a mixture comprised of PS and these two 

compounds, demonstrating that this mixture constitutes the majority of 

the pheromone. It is as yet unclear whether the lamprey has evolved to 

respond to multiple compounds released by larvae to increase their 

sensitivity to larval odor or to discern it more specifically. Efforts are 

presently underway to elucidate the structures of the unknown 

compounds. Funded by the Great Lakes Fishery Commission.


LARVAL REEF FISH DISCRIMINATE BETWEEN REEF 

ODORS AND MAY USE THIS IN RECRUITMENT. 

Atema J. 1, Gerlach G. 2, Kingsford M. 3 1Marine Program, Boston 

University, Woods Hole, MA; 2Marine Resources, Marine Biological 

Laboratory, Woods Hole, MA; 3James Cook University, Townsville, 

Queensland, Australia 

Larval reef fishes typically have an early pelagic phase from which 

they must return back to the reef environment to survive. The 

discrepancy between passive dispersal models and actual recruitment 

data suggests that these small animals participate actively in the 

recruitment process, but the behavioral mechanisms are not clear. The 

ontogeny of swimming efficiency of several species is now known; 

sensory capabilities remain poorly understood. We have been pursuing 

the olfactory hypothesis that early imprinting on the home reef odor 

allows them to remain near the (natal) reef and perhaps may guide their 

return. We have now demonstrated for different species that at the stage 

that they return to the reef they can discriminate between the odor of 

different reefs and among 5 choices prefer the odor of the reef to which 

they returned. We are now using genetic markers to see if this sensory 

capability has led to strong homing that is reflected in population 

genetic substructuring at the scale of single reefs separated by kilometer 

distances with and without current barriers. 


FRUIT ODOR DISCRIMINATION AND HOST RACE 

FORMATION IN RHAGOLETIS FRUIT FLIES 

Linn C. 1, Nojima S. 1, Roelofs W. 1 1Entomology, Cornell University, 

Geneva, NY 

Rhagoletis pomonella is a model for incipient sympatric speciation 

(divergence without geographic isolation) via host plant shifts. We are 

testing the hypothesis that R. pomonella flies originating from 

hawthorn, apple, and flowering dogwood fruit use fruit volatiles to 

distinguish among their respective host plants. Solid phase 

microextraction combined with gas chromatography and 

electroantennogram detection were used to identify unique blends of 

volatiles from each fruit type. In flight tunnel assays flies preferentially 

flew upwind (>70%) to the volatile blend from their natal host. Field 

tests also showed that over the fruiting season significantly more flies 

were captured with natal fruit volatiles. Because R. pomonella 

rendezvous on or near the unabscised fruit of their hosts to mate, the 

behavioral preference for natal fruit odor translates directly into 

premating reproductive isolation between the fly races. To explore the 

genetic basis of the trait crosses were produced between the different 

fly populations. Flight tunnel tests showed that hybrid flies have 

significantly reduced response levels to natal or combined volatile 

blends, with only 40% of the flies exhibiting upwind flight, and only 

with a concentration ten times that used with parent flies. Flies 

generated from F2 crosses exhibited response profiles similar to F1 

hybrids (60%) or to the parent populations (40%). The behavioral data 

lay the foundation for QTL analysis. Supported by NSF DEB-9977011. 

69 


CO2 IS INVOLVED IN THE OVIPOSITION BEHAVIOR OF 

MANDUCA MOTHS 

Guerenstein P.G. 1, Abrell L. 2, Mechaber W.L. 1, Stange G. 3, Hildebrand 

J.G. 1 1ARL Division of Neurobiology, Univ. of Arizona, Tucson, AZ; 

2Biosphere 2 Chemistry Unit, Columbia Univ., Oracle, AZ; 3Biological 

Sciences, Australian National Univ., Canberra, Australia 

Moths detect CO in the environment, but the role of CO in the 

2 2 

biology of these insects is not well understood. It has been suggested 

that CO plays a role in the oviposition of the moth Cactoblastis 

2 

cactorum and in the nectar foraging of Manduca sexta. We asked if 

CO also plays a role in oviposition in Manduca. Two groups of plants, 

2 

each surrounded by a ring of ductwork, were placed inside a flight cage. 

Fans pumped ambient air into the ducts in which small holes provided 

for gas outflow. CO was injected at the inlet for one group of plants, 

2 

thus generating an artificial plume of high CO around that group. 

2 

Female Manduca were released into the cage singly. We measured 

number of eggs oviposited. We found that, as in Cactoblastis, females 

preferred the control plants (no CO added), possibly because natural 

2 

CO fluctuations generated by the test plants were masked by an 

2 

artificially high CO plume. Thus, CO affects the oviposition behavior 

2 2 

of Manduca. We did not find a dose effect, suggesting that the moths´ 

response was saturated at the CO levels used. The response of 

2 

Manduca was lower than that reported for Cactoblastis. Because 

Cactoblastis oviposits on (CAM) plants that generate sinks of CO on 2 

their surface while Manduca oviposits on plants that are sources of 

CO , we suggest that the expected rise in global ambient CO levels 

2 2 

will affect more strongly moths that rely on CO sinks than those that 

2 

rely on CO sources. [Supported by NSF (IBN-0213032), Columbia 

2 

Chemistry, Biosphere 2] 


DEVELOPMENTAL EXPRESSION AND TISSUE 

DISTRIBUTION OF AN ODORANT-BINDING PROTEIN (OBP) 

IN THE MALE YELLOW FEVER MOSQUITO AEDES 

AEGYPTI 

Bohbot J. 1, Vogt R. 1 1Biological Sciences, University of South 

Carolina, Columbia, SC 

Major concerns of an adult male mosquito are finding mates and food 

sources. While most studies concentrate on female specific olfactory 

processes such as seeking a host for a suitable blood meal, little is 

known regarding other olfactory based behaviors, including those of the 

male. Even less is known at the molecular level. We have cloned and 

characterized an OBP from a male antennal cDNA library. The Aaeg- 

OBP sequence is most similar to members of the Drosophila and 

Anopheles OBP family. Due to the limited amount of material, we used 

the quantitative Real-Time PCR method to measure expression levels 

among different tissues and at different developmental times in both 

males and females. Aaeg-OBP expression is adult and male specific. 

Moreover, its expression is restricted to appendages known to carry 

chemosensory organs, including antennae and wings. The expression of 

this gene in adult but not larval males suggests the protein functions in a 

male specific adult context, mediating chemosensory signals important 

to behaviors that are more relevant to the males than to the females. The 

identification of such neural pathways significantly expands our 

opportunity for developing strategies which disrupt chemosensory 

mosquito behavior and thus mitigate human-mosquito interactions.


MECHANISMS OF ACTION OF DEFENSIVE SECRETIONS OF 

THE SEA HARE APLYSIA CALIFORNICA AGAINST THE 

SPINY LOBSTER PANULIRUS INTERRUPTUS 

Shabani S. 1, Derby C.D. 1, Kicklighter C. 1, Johnson P. 1 1Biology, 

Georgia State University, Atlanta, GA 

Active chemical defenses of Aplysia, which include secretions from 

the opaline and ink glands, deter attacks by potential predators. The 

mechanism of action of these secretions differs among predators. 

Against the sea anemone Anthopleura sola, ink from Aplysia 

californica contains a protein that is aversive and cytolytic (Kicklighter 

et al., 2004 AChemS poster). Against the spiny lobster Panulirus 

interruptus, sea hares that release secretions upon attack are more likely 

to be dropped, allowing sea hares to escape. Ink and opaline appear to 

protect sea hares through a combination of phagomimicry, chemical 

confusion, and aversion. Phagomimicry, in which predators are 

deceived into attending to a false food stimulus from the secretions, and 

chemical confusion occur because the defensive secretions contain 

millimolar concentrations of amino acids and coat the sensory organs of 

lobsters. These levels of amino acids in ink and opaline are enormously 

stimulatory to the lobster´s chemosensory cells, and the stickiness likely 

causes a persistent stimulation. The aversive effect against lobsters is 

mediated by components in opaline. In addition, ink and opaline are 

highly acidic (4.9 and 5.8 respectively), suggesting that pH may have 

either a direct or indirect effect on the secretions´ efficacy. We are 

currently examining these pH effects in behavioral and 

electrophysiological assays. Supported by NSF IBN-0324435 


PROTEIN-MEDIATED DEFENSE IN APLYSIA CALIFORNICA 

AGAINST THE PREDATORY ANEMONE ANTHOPLEURA 

SOLA 

Kicklighter C. 1, Johnson P. 1, Yang H. 1, Tai P. 1, Derby C. 1 1Biology, 

Georgia State University, Atlanta, GA 

The sea hare Aplysia californica defends itself from predators with 

two secretions, ink and opaline, which affect predators differently. 

Against the spiny lobster Panulirus interruptus ink is attractive while 

opaline is aversive (Shabani et al., 2004 AChemS poster). Conversely, 

against the predatory sea anemone Anthopleura sola, ink is aversive, 

causing tentacles to shrivel and the gastrovascular cavity to evert. 

Opaline appears to stimulate feeding, as it elicits tentacle movement to 

the mouth, which opens. Our investigations indicate that ink contains 

one dominant protein, “escapin”, which occurs at a concentration of 

0.025 mg/ml of ink. When applied to anemone tentacles, escapin elicits 

cell lysis, suggesting that escapin may be responsible for ink´s 

aversiveness to sea anemones. To further pursue escapin´s defensive 

role for Aplysia, we are using the technique RNA interference to knock 

down production of escapin. Ink produced by Aplysia injected with 

double-stranded RNA elicits less tentacle shriveling than ink produced 

by control Aplysia. We are currently using this technique to assess the 

survival of sea hares that can and cannot produce ink containing escapin 

against sea anemones. 

Supported by NSF IBN-0324435 

70 


PREDATOR ODORS AND REPRODUCTION IN HOUSE 

MOUSE UNDER LABORATORY AND SEMI-NATURAL 

CONDITIONS 

Voznessenskaya V. 1, Naidenko S. 1, Dulchenko N. 1, Clark L. 2 1Institute 

of Ecology & Evolution RAS, Moscow, Russia; 2Repellents, National 

Wildlife Research Center, Fort Collins, CO 

We examined the influence of predator odors (Felis catus) on 

reproductive output of House Mouse (Mus musculus) under laboratory 

and semi-natural conditions. Laboratory naive animals responded to 

predator chemical cues either with block of pregnancy or reduced litter 

size and skewed sex ratio. Under laboratory conditions block of 

pregnancy in experimental group was observed twice higher then in 

both of the control groups (p< 0.001). In enclosures 30% of females 

were not pregnant (season of May-September 2002-2003) when cat 

urine was applied onto the bedding each other day. At the same time in 

control enclosure 92 % (n=38) of females were pregnant. The total 

number of offspring in control enclosure also was significantly higher 

(p< 0.001) then in experimental one. We observed seasonal changes in 

sensitivity of mice to predator chemical cues. It is noteworthy that 

suppression of rodent reproduction also occurred when rodents were 

exposed to urine of conspecifics housed under high population 

densities. The fact that mice respond to certain chemical signals in 

predator urine in similar fashion may be fortuitous, and may have more 

to do with the coincidence that the urine contain similar chemical cues 

resulting from protein digestion in carnivores and protein catabolism in 

nutritionally deprived rodents rather than specific predator-prey 

adaptations. 

Supported by RFBR & Presidium RAS “Biological Resources” # 

3.1.1. 


MANUFACTURE AND TESTING OF CHEMICAL-SIGNAL- 

ENHANCED DEVICES FOR DETERRING CROP-RAIDING 

ELEPHANTS 

Rasmussen L.E. 1, Riddle S.W. 2, Roeder H. 2 1OGI School of Science & 

Engineering, OHSU, Beaverton, OR; 2Riddle's Elephant & Wildlife 

Sanctuary, Greenbrier, AR 

Human-elephant conflict is a significant economic and ecological 

problem in southeast Asia, escalating as human populations continue to 

expand and the forest habitat for elephants is destroyed. In their native 

society Asian elephants utilize two pheromones that elicit well-defined 

behavioral responses and a variety of chemical signals that influence 

other behaviors including movement and choices. Utilizing this 

information combined with several years of testing various antifeedants 

and deterrents, and detailed first-hand knowledge of the 

walking behavior of elephants, Riddle and Rasmussen invented a 

mechanical device, enhanced with chemical signal dispersion units. 

Recently we built twelve such devices at a village site in southern India 

and tested their efficacy during harvest season, the period of maximum 

crop-raiding by elephants. As crop-raiding in this region occurs 

primarily nocturnally, observations were conducted using night vision 

recording equipment. Results demonstrate that 1. the manufacturing 

process was cost effective 2. the devices were efficacious as deterrents 

3. new ambulatory capabilities and high risk behaviors by wild male 

elephants were revealed. We present this study in the context of the 

relevance of basic behavioral and chemical signal research toward 

practical economic use. Supported by USFW grants # 98210-G091to 

LELR and # 98210-3-G648 to LELR and SR.

273 Poster [ ] Accessory Olfactory System 

MODIFICATION OF ODOR INVESTIGATION BY FEMALE 

OPOSSUMS (MONODELPHIS DOMESTICA) AFTER 

ACCESSORY OLFACTORY BULB ABLATION 

Zuri I. 1, Halpern M. 1 1Anatomy & Cell Biology, Downstate Medical 


Monodelphis domestica are South American marsupials that 

commonly scent-mark their environment. We have previously shown 

that female opossums discriminate between conspecific odors from 

different sources. The purpose of the present study was to determine if 

the vomeronasal system is important for females to discriminate these 

odors. 

Investigation of conspecific odors and distilled water was tested in 

12 female opossums in a 2-choice paradigm and the time spent in snout 

contact with each stimulus was analyzed from video recordings. 

Females were tested before treatments and after control treatment 

(anaesthesia and partial elctrolytic accessory olfactory bulb lesions 

(AOBP, N=6), or anaesthesia followed by complete AOB ablation 

(AOBX, N=6)). Neither anesthesia nor AOBP had an effect on odor 

investigation. 

AOBX resulted in a significant reduction of investigation of certain 

odors, but only when those odors were paired with certain other odors. 

For example, when male suprasternal gland (SG) odor was paired with 

urine of the same stimulus male, there was a significant decrease in the 

time spent investigating SG odors following AOBX. However, AOBX 

did not modify the investigation of male SG when it was paired with the 

same-male sub-mandibular odors. 

Our data suggest that the accessory olfactory system may be 

important for the investigation of conspecific odors by female 

opossums, but it does not appear to be essential for such odor 


Supported by NIH Grant DC02745. 


TWO POPULATIONS OF GRANULE CELLS IN THE 

ACCESSORY OLFACTORY BULB OF THE OPOSSUM, 

MONDELPHIS DOMESTICA 

Jia C. 1, Halpern M. 2 1Anatomy and Cell Bliology, Downstate Medical 

Center, Brooklyn, NY; 2Anatomy & Cell Biology, Downstate Medical 


In the accessory olfactory bulb (AOB) the principal neurons, 

mitral/tufted cells, receive synaptic inputs from vomeronasal receptor 

cell axons. Mitral/tufted cell activity is modulated by feedback control 

of interneurons. Granule cells are the major type of inhibitory 

interneurons. In this study, we used immunocytochemical technique to 

analyze the expression of the calcium binding proteins calretinin and 

calbindin D28k in the granule cell layer of the opossum AOB. We 

identified two separate populations of granule cells in the granule cell 

layer. One population expresses only calretinin, and the other expresses 

only calbindin D28k. Their somatic distribution in the granule cell layer 

was intermingled and their dendritic projection into the external 

plexiform layer was also similar. No such differential expression of the 

calcium binding proteins was detected in the mouse or rat AOB, or in 

the main olfactory bulbs of the rat, mouse and opossum using the same 

antibodies. This observation suggests that in the opossum AOB the 

granule cell population is not homogenous. 

Supported by NIDCD grant #DC02745 

71 


VOMERONASAL AND OLFACTORY CONVERGENCE IN 

MEDIAL AMYGDALA 

Case G.R. 1, Meredith M. 2 1Neurosciences Program, Florida State 

University, Tallahassee, FL; 2Neuroscience Program, Florida State 

University, Tallahassee, FL 

Conspecific chemosensory signals communicate social information 

in hamsters, and are distinguished from heterospecific, socially nonrelevant, 

stimuli by Fos responses within medial amygdala (Westberry 

and Meredith AChemS 2003). Signals stimulate the vomeronasal organ 

(VNO) or main olfactory system, activating medial amygdala via 

accessory and main olfactory bulbs (AOB, MOB). We used electrical 

stimulation of the VNO and MOB in anesthetized hamsters to show that 

both systems have input to the medial amygdala. MOB electrodes were 

in the rostro-lateral bulb to avoid driving VNO nerves. Simultaneous 

recordings were made with 4 electrodes inserted into a 3 x 8 grid 

pattern (200 um spacing) covering most of the anterior (MeA) and 

posterior (MeP) medial amygdala. Robust field potentials appeared 

throughout with moderate to high stimulus intensity (400-1000 uA, 

500uS) and a few single units were driven by both systems. Full 

mapping of MeA and MeP was obtained in 5 hamsters and partial 

mapping of MeP in 2 others, as verified by histology. Olfactory input 

clearly has access to medial amygdala even though it was not 

necessary, in the previous Fos studies, for stimulus categorization by 

MeA/MeP. Electrical VNO stimulation in awake hamsters activated Fos 

expression in MeA but not MeP (as for heterospecific chemosensory 

stimulation). Here we found approx equal efficiency for short-latency 

VNO driven activation of MeA and MeP, possibly due to higher 

stimulus levels than used in awake animals (150uA), or to the 

cumulative effect of activation on Fos expression over 15 min. These 

hypotheses will be tested in future experiments. Support by NIDCD 

grant DC005813 


CATEGORIZATION OF CHEMOSENSORY INPUT IN 

MEDIAL AMYGDALA REQUIRES VOMERONASAL INPUT IN 

BOTH SEXUALLY NAÏVE AND EXPERIENCED MALE 

HAMSTERS. 

Westberry J. 1, Samuelsen C.L. 2, Meredith M. 1 1Program in 

Neuroscience, Florida State University, Tallahassee, FL; 

2Neuroscience, Florida State University, Tallahassee, FL 

In male hamsters, medial amygdala responds categorically to 

chemosensory input based on the species and social relevance of a 

stimulus. Using immediate early gene (IEG) expression, we have 

demonstrated that the anterior medial amygdala (MeA) responds to both 

conspecific and heterospecific stimuli, but posterior medial amygdala 

(MeP) responds only to conspecific (socially-relevant) stimuli. Another 

part of the amygdala, the largely GABAergic intercalated nucleus 

(ICN) was activated when MeP was not activated with heterospecific 

stimuli, suggesting inhibition of MeP by ICN. This categorization 

appears to be hard-wired. In sexually-naïve males, lesions of the main 

olfactory epithelium (OLFX) did not change the pattern of IEG 

activation in the MeA or MeP elicited by conspecific and heterospecific 

stimuli, while removal of the VNO (VNX) eliminated categorization 

and most of the responses in the MeA and MeP. Sexually-experienced 

males can use main olfactory input to compensate for lack of VNO 

input. Here we investigated activation and categorization in MeA and 

MeP in experienced-VNX males. Preliminary data indicates that 

experienced-VNX males show activation of MeA and MeP with both 

conspecific and heterospecific stimuli, indicating a lack of 

categorization of these stimuli. Without VNO input, there was never 

activation of ICN with either class of stimuli. There were no significant 

differences in attention to the stimuli (on swabs) that could account for 

differences in amygdala FRAs expression between groups. Supported 

by DC-005813 from NIDCD.


CORTICAL RESPONSE TO ANDROSTADIENONE WITH OR 

WITHOUT FUNCTIONAL OCCLUSION OF THE 

VOMERONASAL DUCT - A FUNCTIONAL MAGNETIC 

RESONANCE IMAGING (FMRI) STUDY 

Gerber J.C. 1, Lundstrom J.N. 2, Frasnelli J. 3, Knecht M. 3, Olsson M. 2, 

Hummel T. 3 1Neuroradiology, Dresden University, Dresden, Germany; 

2Psychology, Uppsala University, Uppsala, Sweden; 

3Otorhinolaryngology, Dresden University, Dresden, Germany 

There has been controversy as to whether the vomeronasal duct 

(VND) in humans is mediating any sensory information or is merely a 

nonfunctional vestige. This study assessed the cortical responses 

following stimulation with the putative pheromone Androstadienone 

(AND) in women, with and without coverage of the VND and using 

AND in concentrations beyond olfactory threshold. We hypothesised 

that activation is independent of the VND´s status. Following detailed 

examination including tests for olfactory functions, 16 women (age 

range 21 to 27 years), fertile, and all presenting with a VND underwent 

fMRI. The odour stimuli were AND (3 mol/l) and phenylethyl alcohol 

(PEA) (pseudo randomised block design, 30s on, 30s off; 1s stimulus 

duration, 3s interstimulus interval). Subjects did not know about the 

status of the VND´s coverage. Imaging data were analysed with SPM2. 

In a group random effects analysis, coverage of the VND did not show 

significant influence on cortical activation. On first sight, AND 

produced an activation pattern similar to that of the control odour PEA. 

When further assessing the differences (AND vs. PEA, group random 

effects analysis), significant subcallosal activation extending to the 

septal region was detected. In summary, access to the VND does not 

seem to play a major role in the perception of AND odor. The 

subcallosal and septal activation specific to AND is in line with 

previous findings with PET. Support: DFG HU441-2, HSFR:F0868 


CHARACTERISTICS OF GENERAL AND SPECIFIC 

CHEMOSENSORY RESPONSES IN THE SNAKE ACCESSORY 

OLFACTORY BULB 

Cinelli A. 1, Li C. 2, Wang D. 3, Liu W. 4, Chen P. 3, Halpern M. 5 

1Downstate Medical Center, Brooklyn, NY; 2Anatomy & Neurobiology, 

University of Tennessee, Memphis, TN; 3Biochemistry, Downstate 

Medical Center, Brooklyn, NY; 4Anatomy and Cell Biology, Downstate 

Medicall Center, Brooklyn, NY; 5Anatomy & Cell Biology, Downstate 

Medical Center, Brooklyn, NY 

Converging evidence indicates that the main olfactory system detects 

general odors using a combinatorial coding strategy. Currently, the 

coding strategy in the vomeronasal (VN) system is unknown, but this 

system detects highly selective chemosignals, and probably depends on 

the activation of highly tuned VN receptor neurons. In snakes, the VN 

system is critical for detecting chemosignals emitted by conspecifics 

and prey, but also responds to general odors and amino acids when they 

are delivered as liquid stimuli. Using voltage sensitive dyes and 

selective chemoattractants, we studied the distribution of neural 

responses evoked by electrical, general and specific chemosensory 

stimuli in the snake accessory olfactory bulb (AOB). All stimulus types 

evoke non-homogeneously distributed patterns within and throughout 

the layers, and seemed to be organized in clusters. The spatial 

distribution of responses to prey chemicals suggest the presence of a 

zone of preferential activation located in the posterior AOB. Changes in 

the spatial distribution of activity occurred over time, suggesting a 

stimulus-specific dynamic organization of responses. Foci of activity 

also exhibited dissimilar thresholds. These results suggest that sensory 

discrimination in the snake AOB is based on a combinatorial coding 

scheme. 

Supported by NIH DC 03735 

72 

279 Slide [ ] Olfactory Sensory Neuron Physiology 

CHLORIDE HOMEOSTASIS IN MOUSE ORNS 

Reisert J. 1, Yau K. 1, Bradley J. 1 1Department of Neuroscience/HHMI, 

Johns Hopkins University, Baltimore, MD 

Olfactory transduction was seen as a system that worked analogously 

to vertebrate phototransduction: Stimulation of G protein-coupled 

receptors triggers an electrical response by activating CNG channels. 

This view was altered when Kleene & Gesteland reported the presence 

of a Ca2+-activated Cl channel on olfactory cilia. Odor stimulation 

increases the ciliary Ca2+ concentration by opening CNG channels, 

generating a secondary Cl current. This current is inward, therefore 

excitatory, implying a relatively high internal chloride concentration. 

80% of the odor-induced current in rodents and 36-65 % in amphibians 

is carried by chloride. Two functions for this unusual Cl current have 

been proposed. First, it provides a nonlinear, low-noise amplification of 

the CNG current. Second, it reduces the dependency of the receptor 

current on external mucosal Na+, which might vary depending on the 

environment, a situation more relevant for amphibians and fish than for 

mammals. Many of the characteristics of the odor-induced response 

therefore depend on the interplay between the CNG channel (the Ca2+ 

source) and the Cl channel, and their regulation. Furthermore, since 

spike frequency is a function of the overall receptor current, the 

interaction of these two channels will affect action-potential generation. 

We present molecular and electrophysiological evidence for a 

mechanism by which internal Cl– concentration is maintained such that 

its reversal potential is positive relative to the resting membrane 

potential in mouse ORNs. 

280 Poster [ ] Olfactory Sensory Neuron Physiology 

CHLORIDE HOMEOSTASIS IN MOUSE OLFACTORY 

NEURONS 

Delay R. 1, Verret T. 1, Gorman R. 1 1Biology, University of Vermont, 

Burlington, VT 

Intracellular Cl, [Cl]i, is important in determining the ultimate 

response of olfactory sensory neurons (OSNs) exposed to odor. 

Although secondary to the non-selective cation current, the Cadependent 

Cl current is primarily responsible for the generator 

potential. Thus, Cl homeostasis is important to odor responses. We used 

MEQ, a chloride sensitive fluorescent dye, to measure [Cl]i across a 

population of isolated OSNs. Since MEQ is a non-ratiometric dye, a set 

of Cl bath standards was used to establish the initial level of internal Cl. 

Our results indicated a wide range of [Cl]i exist in isolated OSNs 

(range: 20-145 mM; mean: 62 mM). As a control, [Cl]i measured in 

erythrocytes had a mean of 55 +/- 5 mM, similar to other reports for 

RBCs. Although the population of isolated OSNs displayed a wide 

range of [Cl]i, in any individual OSN [Cl]i was stable during the 

recording period (up to two hours). The only changes observed in [Cl]i 

were due to stimulation or altering bath conditions to affect Cl 

cotransporters. [Cl]i of OSNs responded in a dynamic fashion, changing 

in response to odor stimulation or by increasing [cAMP]i. With [Cl]i 

unusually high in some olfactory neurons, there must be an active 

transporter or exchanger(s) that maintains this gradient. Several 

different transporters have been reported to carry Cl in neurons. We 

focused on NKCC1 and KCC2 since these Cl cotransporters have been 

shown to be critical to [Cl]i in developing neurons. Drugs were used to 

selectively inhibit either NKCC1 or KCC2. Data from these 

experiments, imaging and perforated patch clamp, suggest these 

transporters are functional in OSNs and work to set [Cl]i.


EXPRESSION OF CL- COTRANSPORTERS IN MOUSE 

OLFACTORY NEURONS. 

Schannen A.P. 1, Delay R.J. 2 1Biology, University of Vermont, 

Burlington, VT; 2Biology Department, University of Vermont, 

Burlington, VT 

Chloride fluxes and intracellular Cl, [Cl]i, are important in 

determining the ultimate response of olfactory sensory neurons (OSN) 

exposed to odor. In some OSNs, Cl can contribute most of the odorelicited 

generator current, giving it a vital role in olfactory signaling. 

Populations of isolated mouse OSNs have been shown to express a 

wide range [Cl]i. To determine what Cl transporters might be involved 

in this variance we characterized the expression of two chloride 

cotransporters in mouse OSNs: isoform 1 of the Na/K/2Cl cotransporter 

(NKCC1) and isoform 2 of the K/Cl cotransporter (KCC2). NKCC1 

moves one Na ion, one K ion and 2 Cl ions into the cell. Conversely, 

KCC2 moves 1 K and 1 Cl ion out of the cell. Since these are 

cotransporters, if any one of ions being moved across the membrane is 

not present, no movement occurs. Western blots of nasal epithelium and 

immunohistochemistry of sectioned tissues, showed that both KCC2 

and NKCC1 were present in mouse olfactory neurons and both 

transporters appeared to be located in the apical region of OSNs. To 

further characterize the expression patterns of KCC2 and NKCC1 we 

examined isolated cells using deconvolution microscopy. OSNs showed 

variable expression of KCC2 and NKCC1. Some OSNs displayed 

intense labeling for NKCC1 and KCC2 in their dendritic region, while 

others express these cotransporters at lower levels throughout the entire 

cell. A few OSNs showed only faint expression of either cotransporter. 

We have shown that NKCC1 and KCC2 are present in mouse OSNs, 

although expression is not uniform across the population of OSNs. 

Supported by NIH grants P20RR16435 & P20RR16462 


PENDRIN, A CHLORIDE TRANSPORTER, IS EXPRESSED IN 


Kleene N.K. 1, Zhang J. 1, Pixley S.K. 1, Soleimani M. 2, Kleene S.J. 1 1Cell 

Biology, Neurobiology & Anatomy, University of Cincinnati, 

Cincinnati, OH; 2Internal Medicine, University of Cincinnati, 

Cincinnati, OH 

During odorant transduction, a calcium-activated chloride current 

contributes to the depolarization of olfactory receptor neurons (ORNs). 

The purpose of this study is to identify anion exchangers that regulate 

internal chloride concentration in ORNs. Toward this end, reverse 

transcriptase-polymerase chain reaction was performed on RNA 

isolated from murine nasal mucosa using primers specific for members 

of the SLC26 family, a highly conserved group of anion exchangers 

that transport chloride. Our results identified the expression of pendrin 

in murine nasal mucosa. Pendrin is an ion transporter that exchanges 

chloride for bicarbonate, hydroxide, iodide, or formate but not sulfate. 

It also exchanges chloride for fructose and mannose. Pendrin is 

abundantly expressed in a distinct subpopulation of cells in the thyroid, 

inner ear, and kidney. Mutations in pendrin cause Pendred´s syndrome, 

a hereditary disorder characterized by deafness and goiter. Using 

Northern blotting, we confirmed that pendrin mRNA is expressed in 

nasal mucosa. Immunohistochemical staining with specific antibodies 

indicated that pendrin is expressed in ORNs and sustentacular cells in 

the epithelium, as well as in mitral cells in the olfactory bulb. In ORNs, 

sustentacular cells and mitral cells, pendrin is present in spherical, 

vesicle-like structures. The immunolabeling was specific since it was 

blocked with the pendrin peptide to which the antibody had been raised. 

Future studies are aimed at identifying the vesicles that express pendrin 

and in ascertaining the role of pendrin in regulating chloride 

concentration in the ORNs. This work was supported by NIH grant R01 

DC00926 (SJK) and DK 62809 (MS). 

73 


PLASMA MEMBRANE CALCIUM PUMPS IN THE MOUSE 

OLFACTORY AND VNO RECEPTOR CELLS 

Cusick M. 1, Chandran S. 1, Van Houten J. 1, Delay R. 2 1Biology, 

University of Vermont, Burlington, VT; 2Biology Department, University 

of Vermont, Burlington, VT 

Calcium (Ca) plays important roles in olfactory signaling and, 

therefore, it must be important to control intracellular Ca levels in 

olfactory and VNO sensory neurons by binding proteins, intracellular 

pumps, and extrusion from the cell by the Na+/Ca2+ transporter and 

plasma membrane Ca pumps (PMCAs). Mammals have 4 PMCA 

isoforms, each with different kinetic properties to serve different 

physiological tasks. We are studying the distribution and roles of these 

pumps in olfactory and VNO receptor neurons using 

immunocytochemistry of epithelia and dissociated cells and calcium 

imaging. The pan-PMCA antibodies show distinct staining patterns in 

the olfactory and VNO epithelia: intense in the apical region of the 

olfactory epithelium but not in the respiratory epithelium; none apparent 

in the cilia; faint in the region of the neuron cell bodies. Use of specific 

antibodies shows: intense staining for isoforms 1 and 2 in both VNO 

and olfactory epithelium; little or no staining for isoforms 3 and 4 in 

either epithelium; weak to no staining of any isoform in the respiratory 

epithelium. The most intense staining is in VNO for isoforms 1 and 2 

and in olfactory epithelium.Dissociated olfactory sensory neurons 

(OSNs) show staining for isoform 1 along the entire cell with intense 

staining where the dendrite meets the cell body. Staining for isoform 2 

is prominent at the dendritic knob, cilia and cell body with less in the 

dendrite. Calcium imaging of isolated OSNs shows that calcium levels 

can return to basal levels after KCl or odorant stimulation even in the 

absence of transporter and SERCA pump function, which suggests a 

role for PMCAs in Ca removal in response to odor stimulation. 

Supported: NIH DC00721, P20RR16435, NCI PHS22435


OLFACTORY EPITHELIAL LOCALIZATION AND 

DENDRITIC MORPHOLOGY OF GOLF NEGATIVE 

OLFACTORY SENSORY NEURONS PROJECTING TO 

MEDIAL OLFACTORY BULB GLOMERULI IN THE LARVAL 

SEA LAMPREY (PETROMYZON MARINUS. L) 

Firby A.E. 1, Arbuckle W.J. 1, Zielinski B.S. 1 1Biological Sciences, 

University of Windsor, Windsor, Ontario, Canada 

Firby, A.E., Arbuckle, W.J., Zielinski, B.S. 

Abstract 

The objective of this study is to examine the dendritic morphology 

and olfactory epithelial distribution olfactory sensory neurons (OSNs) 

that project to spatially conserved medial glomeruli in the sea lamprey, 

an ancestral vertebrate with migratory and reproductive behavior 

mediated through pheromones (Li et al., 1995 J. Gen. Physiol. 105: 

567; Li et al., Science 2002 296: 138-141). These medial glomeruli 

lack Golf,expression; yet this GTP binding protein is localized in the 

remaining six glomerular territories (Frontini et al., J Comp Neurol 

465:27-37). Following micro-injection of fluorescent dextran amines 

into the medial glomeruli, dextran labeled OSNs were observed in the 

ventral hemisphere of the olfactory mucosa. The dendrite of these 

OSNs was long and slender, and the cell body was located in the basal 

half of the olfactory epithelium. In comparison, Golf- immunoreactive 

OSNs were widely distributed in the olfactory epithelium. The 

morphology of the Golf-immunoreactive OSNs included short, thick 

dendrites with cell bodies in the apical portion of the olfactory 

epithelium, and OSNs with slender dendrites and cell bodies in the basal 

half of the olfactory epithelium. This study shows that OSNs in the sea 

lamprey are dimorphic, and supports the idea that sub-populations of 

OSN terminals are distributed according to functional parameters in this 

species. 

Supported by: Great Lakes Fishery Commission, NSERC, University 

of Windsor Faculty of Graduate Studies 

74 


ELECTROPHYSIOLOGY OF SUSTENTACULAR CELLS IN 

MOUSE OLFACTORY EPITHELIUM (OE) 

Vogalis F. 1, Hegg C. 1, Lucero M. 1 1Physiology, University of Utah, Salt 

Lake City, UT 

Sustentacular cells (SCs) are exquisitely sensitive to P2Y receptor 

stimulation and generate robust increases in [Ca2+ ] implicating ATP as 

i 

an important paracrine regulator in the OE1 . Here we determined the 

electrical properties and responses to ATP of SCs in 250-µm OE slices 

from mice (P1-P4) using whole-cell techniques. Capacitances (C ) of m 

SCs averaged 17.9 ± 0.1 pF and input resistance (R ) was 173.1 ± 15.6 

in 

MΩ (n = 134). SCs generated a fast inward Na + current that was halfmaximally 

activated and inactivated at –52 mV and –86 mV 

respectively. Blocking gap junctions with 1 mM 1-octanol did not 

significantly alter C (20.9 ± 1.4 pF before vs. 20.7 ± 2.2 pF during 1- 

m 

octanol, n=11) while R increased significantly (p < 0.05, paired t-test) 

in 

from 140 ± 48 MΩ to 187 ± 58 MΩ. The poor electrical connectivity 

between SCs was confirmed by an absence of dye coupling in 8 of 10 

cells filled with Lucifer Yellow (0.2%). In the presence of 1-octanol, 

ATP (30-s, 20-50 µM) transiently decreased R by 10%, which then 

in 

increased by 20% during the 5 min wash. In 8 SCs, a 30-s application 

of ATP increased C by ~ 2.5% over 10 min. Our results indicate that 

m 

SCs generate inward Na + currents which, due to the low R of SCs, 

in 

cannot support action potentials. The low R is apparently not due to 

in 

coupling to neighboring cells. In addition, ATP elicits a biphasic 

response in the R of SCs and may trigger exocytosis as indicated by ~ 

in 

400 fF increase in C . Further experiments will identify the resting 

m 

conductances of SCs and those elicited by ATP, as well as the Ca2+ - 

dependence of the ATP-mediated exocytosis. Funded by NIDCD 

DC02994toMTLand DC04953 toCCH.1.Heggetal.,J.Neurosci.23: 

8291-8301.


TRANSCRIPTS ENRICHED IN SENSORY NEURONS AND 

SUPPORTING CELLS OF THE OLFACTORY EPITHELIUM 

Yu T. 1, Mcintyre J.C. 1, Bose S.C. 1, Hardin D. 1, Mcclintock T.S. 1 

1Physiology, Cell and Molecular Sensory Systems Program, University 

of Kentucky, Lexington, KY 

Using a fluorescent LacZ substrate and flow cytometry, we collected 

LacZ+ and LacZ- cells from the olfactory epithelium of OMP-LacZ3 

mice (Walters et al., 1996, J Neurosci Res. 43:146). Olfactory marker 

protein was 100-fold enriched in the LacZ+ RNA, indicating successful 

purification of mature olfactory sensory neurons (OSNs). 

Representational difference analysis confirmed by quantitative RT-PCR 

identified 54 differentially distributed transcripts. The majority of these 

transcripts encode proteins that have no known function. In situ 

hybridization identified 11 transcripts expressed only by OSNs and 

vomeronasal sensory neurons (VSNs). Some were restricted to mature 

OSNs. Twelve additional transcripts were enriched in OSNs and 

VSNs, but were also expressed in other cells in the epithelium. One 

novel transcript was expressed in the OSNs, sustentacular cells, and 

Bowmans glands only within a restricted region of the epithelium. The 

six transcripts restricted to sustentacular cells and Bowman´s glands 

include several enzymes that metabolize odorants. We also identified a 

transcript, pancreatitis-associated protein, restricted to cells of the 

respiratory epithelium. As a group, these olfactory enriched transcripts 

provide useful markers of certain cell types within the epithelium and 

potential insights into the function of several of these cell types. 

Supported by R01 DC02736 and R01 AG18229. 


EXPRESSION PROFILING OF PHENOTYPICALLY 

IDENTIFIED OLFACTORY SENSORY NEURONS 

Mcintyre J.C. 1, Yu T. 1, Shetty R.S. 1, Sammeta N. 1, Smith M.A. 1, 

Mcclintock T.S. 1 1Department of Physiology, University of Kentucky, 

Lexington, KY 

GFP+ and GFP- cells were collected using flow cytometry from the 

olfactory epithelium of OMP-GFP mice (Potter et al., 2001, J Neurosci. 

21:24). RNA from these two populations of cells, and from the brain of 

OMP-GFP mice, was hybridized against Affymetrix MOE430 A and B 

GeneChip microarrays. Adenylyl Cyclase type III and G were 

&alphaolf 

present in the GFP+ RNA but not detected in the GFP- RNA, indicating 

that olfactory sensory neurons (OSNs) were enriched in the GFP+ 

population. We identified 730 probe sets that were present only in the 

GFP+ population. Of these, 490 represent expressed sequence tags 

(ESTs), genes encoding proteins of unknown function, and unannotated 

genes. A wide range of functions were represented by the other 240 

sets. Transcripts were detected with roles in odorant detection (22), cell 

adhesion (10), metabolism and biosynthesis (21), transcription 

regulation (11), cell signaling (16), proliferation and differentiation 

(19), ion permeation and small molecule transport (24), and 

intracellular transport (9). Comparisons to previous experiments 

profiling transcripts expressed in the olfactory epithelium or in OSNs 

revealed overlaps with less than 5% of our list. Our data therefore 

appear to greatly expand the number of transcripts known to be 

enriched in OSNs. 

Supported by R01 DC02736 and R21 DC4507. 

75 


HOW SENSITIVE CAN A `BROADLY TUNED´ OLFACTORY 

RECEPTOR BE? 

Nickell T. 1 1Cell Biology, Neurobiology and Anatomy, University of 


There is an apparent paradox in the current literature of vertebrate 

olfaction. On the one hand, many kinds of evidence show that receptors 

are `broadly tuned´; each receptor responds to numerous compounds. 

On the other hand, mammals can detect very low concentrations of 

odorants and single receptor neurons may detect single odorant 

molecules. Broad tuning appears to require low-affinity binding of 

odorants; high sensitivity is most easily explained by high-affinity 

binding. Thus, there appears to be an inverse relation between 

sensitivity and `broad tuning´. We have used a simple model to explore 

this tradeoff. 

To obtain sensitivity near the theoretical limit of one molecule, one 

bound ligand--or one active receptor--must produce spikes in the 

olfactory neuron. Amplification mechanisms within the cell can 

accomplish this; however, in a receptor with low affinity and binding 

energy thermal fluctuations may produce a significant probability of the 

active state in the absence of a ligand. Unless the total spontaneous 

activity of all the receptors in the cell is well below threshold, these 

thermal fluctuations will produce spikes. This requirement determines a 

minimum energy difference between Active and Inactive states of the 

receptor and, hence, a minimum binding energy and affinity of the 

ligand (odorant). 

Calculations using plausible estimates of the number of olfactory 

receptors in a cell show that at a moderate binding energy, the 

probability of spontaneous receptor activity is low enough to permit a 

cellular response to a single active receptor. 


OLFACTORY ÌNTERFEROMETRY´ - NON-CONTIGUOUS 

DISTRIBUTIONS OF OLFACTORY RECEPTOR NEURONS 

EXPRESSING ONE OLFACTORY RECEPTOR 

Kauer J.S. 1, White J.E. 1 1Neuroscience, Tufts University School of 

Medicine, Boston, MA 

Following elucidation of olfactory receptor (OR) candidates (Buck 

and Axel, 1991), it was shown that olfactory receptor neurons (ORNs) 

expressing one OR (designated here ORNx´s) are positioned in a noncontiguous 

fashion within olfactory epithelial (OE) `zones´ (Ressler et 

al. 1993; Vassar et al.,1993). We have recently shown similar, noncontiguously 

positioned ORNx´s in salamander OE (Marchand et al., 

2004, in revision). From a developmental perspective (how stem cells 

generate one ORNx population) and from a targeting perspective (how 

ORNx´s find glomerular targets in the bulb), it would seem more 

efficient that ORNx´s be in contiguous groups. The question thus arises 

as to what advantages might non-contiguous ORN placement afford. 

In the present study, we hypothesize that non-contiguous ORNx 

placement provides the opportunity for odor-generated activity in each 

ORNx neuron to be compared by the receiving circuitry of the target 

glomerulus with respect to similarity. Responses from ORNx´s placed 

in different regions of the incoming air flow, should be similar because 

they arise in ORNs expressing the same OR. The degree to which such 

responses are seen as similar by glomerular circuits is a measure of 

signal robustness. Such comparisons, especially for near threshold 

signals, performed in appropriate time windows (e.g. during sniffs), can 

provide for a kind of ìnterferometric´ process that could increase 

signal/noise ratio and improve the sensitivity (by averaging) of the 

ensemble, over individual ORN, responses. 

Supported by grants from the NIDCD and ONR.


ASSESSING AIRFLOW PARAMETERS IN RAT EOGS 

Scott J.W. 1, Acevedo H.P. 1 1Cell Biology, Emory University, Atlanta, 

GA 

The chromatographic model of olfactory response by Mozell and 

colleagues predicts that response size should vary with the interaction 

of flow rate and the physicochemical properties of odorants. We 

investigated this question in the rat nose by EOG recordings in the 

dorsal lateral recesses of the intact nasal cavity. Nasal flow rates of 50, 

100, 200, & 500 ml/min were used to characterize the response size and 

latency. We found that latency measurements in the lateral recess had to 

guard against complex waveforms arising from stimulation at other 

sites. These waveforms are artifactual because they do not appear if 

odorants are directly applied to the opened epithelium and they 

disappear if the dorsal recess is made unresponsive by prolonged 

exposure to low molecular weight esters. With isoamyl acetate 

stimulation, the response in the lateral recess grows more rapidly with 

increase in nasal flow rate than the response in the dorsal recess. The 

latency in the lateral recess also decreases as flow rate increases. This 

effect was present over at least a 3 log unit range of concentration, 

down to approximately 10-3 of vapor saturation. We suggest that the 

greater response latency in the lateral sites is indicative of slower 

airflow in the lateral recesses, which would favor odorant sorption 

before it reaches the recording site. As airflow increases, that loss of 

odorant due to sorption is decreased and the response increases 

markedly. This effect is smaller with odorants that normally evoke large 

lateral responses (hexane, α-terpinene, and limonene). We interpret 

these findings to mean that the sniff velocity may dynamically control 

both the timing and size of olfactory responses in different parts of the 

epithelium. Supported by NIH grants DC00113 & DC04710. 


ALTERED OLFACTORY SENSORY NEURON PHENOTYPE IN 

MUCOPOLYSACCHARIDOSES I AND VI 

Rawson N.E. 1, Wysocki L.M. 1, Dankulich L. 1, Gomez G. 2, Haskins M. 3 

1Monell Chemical Senses Center, Philadelphia, PA; 2Biology, 

University of Scranton, Scranton, PA; 3School of Veterinary Medicine, 

University of Pennsylvania, Philadelphia, PA 

Mucopolysaccharides (MPS) are thought to play a role in neural 

development and axon guidance. To assess their importance in the 

olfactory system, we studied the effects of two feline genetic models 

lacking different enzymes involved in MPS processing; one (MPSI) is 

associated with mental retardation, while the other (MPSVI) is not. We 

used tissue obtained at autopsy from unaffected control and affected 

cats. Stimulus-induced changes in intracellular calcium were studied 

using fluorescence imaging of live olfactory sensory neurons (OSNs). 

There were significantly fewer odorant responsive cells in the tissue 

from MPSI affected cats (n = 7; 1/57 ORNs), while about 25% of 149 

cells isolated from controls (n = 18) responded to a standard battery of 

13 odorants. In contrast, the frequency of responses to elevation of 

cAMP or membrane depolarization were similar in OSNs from control 

and affected cats. Fewer OSNs were obtained from animals with 

MPSVI (n=4; 11 OSNs), but they responded normally to odors, 

depolarization and cAMP elevation. These results indicate that the 

defect in alpha-L-iduronidase activity (MPSI), but not arylsulfatase B 

activity (MPSVI) alters the normal development or maintenance of the 

olfactory epithelium. These data suggest that abnormal MPS processing 

interferes with OSN function and that certain MPSs play a role in 

development or maintenance of the olfactory system. Funded in part by 

NIH DK25759 and RR02512 (MH). 

76 


BIOPHYSICAL MODEL OF OLFACTORY RECEPTOR 

NEURON (ORN) PAIRS REVEALS MECHANISM FOR GAP 

JUNCTION MEDIATED SYNCHRONIZED FIRING AT 

THRESHOLD ODOR CONCENTRATIONS 

Buntinas L. 1, Zhang C. 1, Restrepo D. 1 1Cell and Developmental 

Biology, University of Colorado Health Sciences Center, Denver, CO 

Recent studies in our laboratory have shown that multiple connexins 

are expressed in mature ORNs in mice, suggesting that gap junctional 

coupling might modify ORN function. A recent study in Necturus 

maculosus (Delay and Dionne Chem. Senses. 28:807, 2003) found only 

a small fraction of coupled ORNs arguing against a general functional 

role for gap junctions. However, sparse coupling does not imply lack of 

a functional role of gap junctions in sub-groups of neurons expressing 

the same olfactory receptor. If connexins are only expressed in ORNs 

expressing certain olfactory receptors, the function of those ORNs 

could be modulated by gap junctional coupling. We formulated a 

Hodgkin and Huxley compartmental model of two gap junction coupled 

ORNs in order to create the theoretical framework necessary to test the 

hypothesis that gap junctions modulate function of specific subgroups 

of ORNs. We asked how the strength of the coupling would change the 

odor-induced activity of the coupled neurons. We report that at 

intermediate coupling strength, ORNs of different odor specificity 

display synchronized firing at threshold odor concentrations. At higher 

concentrations, the firing is not synchronized and differs substantially 

between the cell that is stimulated with the cognate odor and the 

adjacent cell. This mechanism would allow for increased odor 

sensitivity of certain odors without compromising odor quality 


This work was supported by NIH grants DC00566, DC04657 (DR), 

DC04952 (CZ) and DC006542 (LB). 

293 Poster [ ] Sweet Taste 

REDUCTION OF SWEET-SUPPRESSING EFFECTS OF 

GURMARIN BY KALLIKREINS INCREASED IN THE 

SUBMANDIBULAR SALIVA OF RATS FED GYMNEMA- 

CONTAINING DIET 

Yamada A. 1, Katsukawa H. 2, Sugita D. 3, Ninomiya Y. 1 1Kyushu 

University, Fukuoka, Japan; 2Physiology, Asahi University, Gifu, 

Japan; 3Central Laboratory, Lotte Co., LTD., Saitama, Japan 

A tropical plant, gymnema sylvestre (gymnema), contains gurmarin 

that selectively inhibits responses to sweet substances in rodents. The 

present study investigated possible interaction between gurmarin and 

the submandibular saliva in rats fed diet containing gymnema. At 1-2 

days after the start of the gymnema diet, preference for saccharin and 

D-phenylalanine decreased and subsequently returned closely to the 

control level within several days. Electrophoretic analyses 

demonstrated that relative amounts of two proteins in the saliva clearly 

increased in rats fed the gymnema diet. Rats previously given section of 

the bilateral glossopharyngeal nerve, however, showed no such salivary 

protein induction, suggesting importance of sensory information for the 

protein induction. Analyses of amino acid sequence indicate that two 

proteins are rat kallikrein 2 (rK2) and rat kallikrein 9 (rK9). rK2 and 

rK9, a family of serine proteases, have resemble cleavage sites in the 

protein substrates of which comparable residue is also contained in 

sequence of gurmarin. Finally, kallikreins purified from saliva clearly 

inhibited the immunoreaction between gurmarin and antigumarin 

antiserum. These results suggest that rK2 and rK9 increased by the 

gymnema diet via oral sensory system cleave gurmarin and reduce its 

sweet suppressing effect in rats.


BEHAVIORAL TESTING OF THE INTERACTION OF SWEET 

TASTE AND SOLUTION TEMPERATURE IN THE RAT 

Denbleyker M. 1, Taylor P.A. 1, Smith P. 2, Smith J.C. 1 1Psychology, 

Florida State University, Tallahassee, FL; 2Psychology, Florida 

Southern University, Lakeland, FL 

Electrophysiological recordings have shown that there is an 

interaction between taste and temperature in the rat, but there is scant 

behavioral evidence to support this finding. The present study was 

conducted to test the licking behavior of non-deprived rats in a shortterm 

test using different concentrations of nutritive and non-nutritive 

sweeteners across temperatures ranging from 10° to 40°C. A testing 

apparatus was developed to control the temperature of a solution with a 

resolution of 1° C. An infrared beam was passed across the opening to 

the sipper tube, so when the rat's tongue broke the beam, licks could be 

counted. Shutters could be opened, allowing access to the sipper tubes. 

During daily testing sessions, eight 30s taste/temperature trials were 

given by opening the shutter, allowing the rat access to a sucrose or 

saccharin solution. The inter-trial-interval was 90s, allowing time for 

the temperature of the solution to be raised 5° for the subsequent trial. 

On a given day, the concentration of the sucrose or saccharin was held 

constant and the temperature was varied from 10° to 40° in an 

ascending manner across the 8 trials. Concentrations used for sucrose 

were 0.00075 to 0.25 M and for saccharin 0.001 to 0.066 M. The 

software analysis program allowed for a microanalysis of the licking 

behavior during the 30s presentations. As has been shown, licking 

increases as a function of concentration for sucrose and is expressed as 

an inverted U-function for saccharin. In all cases, licking decreases as 

the temperature of the solution is increased above 22°C. 


MOLECULAR STUDIES OF SWEET TASTE RECEPTOR 

FUNCTION 

Jiang P. 1, Liu Z. 2, Benard L. 2, Snyder L. 1, Margolskee R. 2, Max M. 1 

1Department of Physiology and Biophysics, Mount Sinai School of 

Medicine, New York, NY; 2Department of Physiology and Biophysics, 

Mount Sinai School of Medicine, Howard Hughes Medical Institute, 

New York, NY 

Heterologous expression of T1R2 plus T1R3 yields a functional 

“sweet receptor” that is responsive to a diverse range of sweet tasting 

ligands. Sweet tastants include sugars (e.g. glucose, fructose, sucrose), 

sugar alcohols, small molecule artificial sweeteners (e.g. saccharin and 

acesulfame K) and certain proteins (e.g. brazzein, monellin and 

thaumatin). There is no common structure that unites all of these 

diverse compounds, although several attempts have been made to infer 

a universal sweet motif. Brazzein, like monellin and thaumatin, is a 

naturally occurring protein that humans, apes and old world monkeys 

perceive as intensely sweet, but which is not preferred by, and is 

apparently tasteless to, other species such as new world monkeys, rats 

and mice. 

Using mouse-human T1R chimeras, site-directed mutagenesis and 

calcium imaging of heterologously-expressed T1R2 + T1R3 we have 

determined the molecular basis for this species-specific sensitivity: we 

have identified a site within human TlR3 that is required for brazzein to 

stimulate T1R2 + T1R3. Other mutations in this same region of human 

T1R3 had effects on receptor activity toward monellin, and in some 

cases, overall receptor responsivity toward most or all sweet 

compounds. This suggests that this region of T1R3 may play a role in 

both ligand binding (especially for the protein sweeteners) and in the 

transition between inactive and active states of the receptor. 

77 


ALLELIC VARIATION OF THE TAS1R3 TASTE RECEPTOR 

GENE SELECTIVELY AFFECTS BEHAVIORAL AND 

NEURAL TASTE RESPONSES TO SWEETENERS IN THE F2 

HYBRIDS BETWEEN C57BL/6BYJ AND 129P3/J MICE 

Inoue M. 1, Reed D.R. 2, Li X. 2, Tordoff M.G. 2, Bachmanov A.A. 2, 

Beauchamp G.K. 2 1Tokyo University of Pharmacy and Life Science, 

Tokyo, Japan; 2Monell Chemical Senses Center, Philadelphia, PA 

Recent studies have shown that the T1R3 receptor protein encoded 

by the Tas1r3 gene is involved in transduction of sweet taste. To assess 

ligand specificity of the T1R3 receptor, we analyzed the association of 

Tas1r3 allelic variants with taste responses in mice. In the F2 hybrids 

between the C57BL/6ByJ (B6) and 129P3/J (129) inbred mouse strains, 

we determined genotypes of markers on chromosome 4, where Tas1r3 

resides, measured consumption of taste solutions presented in the twobottle 

preference tests, and recorded integrated responses of the chorda 

tympani gustatory nerve to lingual application of taste stimuli. For 

intakes and preferences, significant linkages to Tas1r3 were found for 

the sweeteners sucrose, saccharin and D-phenylalanine, but not glycine. 

For chorda tympani responses, significant linkages to Tas1r3 were 

found for the sweeteners sucrose, saccharin, D-phenylalanine, Dtryptophan 

and SC-45647, but not glycine, L-proline, L-alanine or Lglutamine. 

No linkages to distal chromosome 4 were detected for 

behavioral or neural responses to non-sweet quinine, citric acid, HCl, 

NaCl, KCl, monosodium glutamate (MSG), inosine 5´-monophosphate 

(IMP) or ammonium glutamate. These results demonstrate that allelic 

variation of the Tas1r3 gene affects gustatory neural and behavioral 

responses to some but not all sweeteners. This study describes the range 

of ligand sensitivity of the T1R3 receptor using an in vivo approach. 

Supported by NIH grant DC00882 (GKB). 

297 Poster [ ] Taste Psychophysics 

PERCEPTUAL VARIANCE: HOW DISCRIMINATION 

METHODS BECOME LESS DISCRIMINATING 

Lee H. 1, Jeon S. 2, Kim K. 3, O'Mahony M. 4 1Food Science & 

Technology, University of California, Davis, Davis, CA; 2Dept Food & 

Nutritional Science, Ewha Womans University, Seoul, South Korea; 

3Dept. Food & Nutritional Science, Ewha Womans University, Seoul, 

South Korea; 4Food Science and Technology, University of California, 

Davis, Davis, CA 

Discrimination tests are incorporated into threshold measurement and 

are used as difference tests, in the sensory evaluation of food. Yet, the 

various methods are not equivalent. This can be understood in terms of 

perceptual distributions (signal & noise) and d'. For a given perceptual 

difference, the greater the variance of these distributions, the smaller 

will be the value of d'. There are several sources of perceptual variance 

that can affect discrimination: adaptation and the sequence of tasting, 

memory and forgetting, and criterion variation. The goal of this study 

was to investigate these effects, using discrimination between purified 

water and `threshold´ concentrations of NaCl. Firstly, the 2-AFC, 

triangle, duo-trio, and same-different methods were compared. Values 

of d' were computed and used for statistical analysis. After warm-up, 

which had the effect of stabilizing its criterion, memory effects 

rendered the same-different test as sensitive as the 2-AFC, despite its 

less advantageous sequence effects. Both were significantly more 

sensitive than the duo-trio or triangle methods. However, without 

warm-up criterion variation reduced the sensitivity of the samedifferent 

method to that of the triangle. Secondly, the effects of 

adaptation were further demonstrated using the two possible 3-AFC 

tests (NaCl-odd vs. water-odd) and varying their relative sensitivity by 

manipulating interstimulus rinses. Either 3-AFC elicited significantly 

higher d' values when the interstimulus rinses were different from the 

stimuli than when they were the same. 

Funding: UC Davis, Ewha WU


BIMODAL DISTRIBUTION OF SUCROSE OCTAACETATE 

(SOA) BITTER TASTE SENSITIVITY, AND HERITABILITY 

OF THIS TRAIT AMONG TWINS 

Tharp A.A. 1, Alarcon S.M. 1, Tharp C.D. 1, Reed D.R. 1, Breslin P.A. 1 

1Monell Chemical Senses Center, Philadelphia, PA 

Sucrose octaacetate (SOA) tastes bitter to most tasters but the degree 

of perceived bitterness varies considerably. SOA is one of the most 

extensively investigated bitter taste traits in mice and has led to the 

identification of the Soa locus on mouse chromosome 6. To determine 

whether human sensitivity to the bitterness of SOA is also a genetic 

trait, we screened 130 mono- and dizygotic twins for their bitterness 

recognition threshold using a modified Harris-Kalmus sort test. In 

addition, these same subjects tasted and rated the bitterness intensity of 

six concentrations (including water) of SOA twice on the general 

Labeled Magnitude Scale. Monozygotic twins share 100% of their 

alleles in common whereas dizygotic twins share 50% of their genes on 

average. Thus, if a perceptual/behavioral trait has a significant genetic 

component, then monozygotic twins should be more similar to each 

other for this trait than are dizygotic twins. We found that the perceived 

bitterness of SOA was more similar among monozygotic twins than 

dizygotic twins for both the Harris-Kalmus test and the bitterness 

ratings. We further found that bitterness ratings were reliable and, at 

low concentrations, formed a bimodally distributed frequency 

histogram due to a subset of the population that cannot taste SOA until 

higher concentrations. At higher SOA intensities, the distribution 

appears more unimodally distributed. We also determined that the 

intensity ratings at low concentrations and the Harris-Kalmus bitterness 

recognition threshold levels were correlated, which validates these 

observations. Human Chr 12 syntenic to the Soa locus on mChr 6 

should yield candidate genes. Reasearch funded by DC02995 to PASB. 


GUSTATORY RESPONSE TIMES TO INTENSITY AND 

HEDONIC JUDGMENTS 

Veldhuizen M.G. 1, Kroeze J.H. 2 1Taste and Smell Laboratory, 

University of Utrecht, Utrecht, Netherlands; 2Taste and Smell 

Laboratory, University of Utrecht, Utrecht, Netherlands 

Choice response times of intensity and hedonic judgments were 

compared. Subjects made forced choice paired comparisons of orange 

lemonades with various concentrations of added quinine sulfate. 

Subjects were instructed to focus either on intensity or on pleasantness. 

Computerized administration of the stimuli and registration of the 

responses enabled response times measurements. Gustatory response 

times to intensity and hedonic judgments were compared in a withinsubjects 

ANOVA. Preliminary results of 24 subjects indicate that a 

focus on intensity or hedonic aspects had no effect on response times 

(F[1,23] = 2.451, p = .131), whereas there was an effect of 

concentration on response times (F[3.69] = 6.164, p = .001). The 

similarity of the response times for intensity and pleasantness may be 

due to the simultaneous availability of hedonic and intensity 

information to cognitive processing. Such a conclusion may be more 

compatible with a model of parallel processing of hedonic and 

perceptual information than with serial models of hedonic and 

perceptual processing. 

Funding by Helmholtz Institute, University of Utrecht 

78 


THERMAL TASTE IS ASSOCIATED WITH GENERALLY 

HIGHER TASTE RESPONSIVENESS. 

Green B. 1, George P. 2 1The John B. Pierce Laboratory and Yale School 

of Medicine, New Haven, CT; 2The John B. Pierce Laboratory, New 

Haven, CT 

It was recently found that for some people, temperature alone can 

stimulate taste sensations (Thermal taste). To investigate a possible 

source of individual differences in thermal taste we tested whether 

sucrose sweetness, which can be modulated by temperature, would be 

rated higher by thermal tasters (n=14) than by thermal non-tasters 

(n=14). Ss used the gLMS to rate taste intensity on the tongue tip for 

three concentrations of sucrose, with saccharin and NaCl included as 

controls. Contrary to the hypothesis, thermal tasters gave higher ratings 

to all three stimuli [F(1,26)=21.0, p


SUCROSE AND SODIUM CHLORIDE SELF-ADAPTATION 

USING “TASTE” 

Ashkenazi A. 1, Gent J.F. 2, Marks L.E. 1, Frank M.E. 3 1J. B. Pierce 

Laboratory and Yale University, New Haven, CT; 2Yale University, 

New Haven, CT; 3University of Connecticut, Farmington, CT 

Recently we developed a computer-controlled, automated, open flow 

system for gustatory research (Ashkenazi, Fritz, Buckley, and Marks, in 

press). Using pressurized air to control delivery of the solutions, this 

system provides precise temporal control over as many as 16 possible 

stimuli. In the current study we tested whether a common finding in the 

taste domain, that of self-adaptation, can be replicated using TASTE 

(Temporal Automated System for Taste Experiments). Subjects rated 

the intensity of either 0.5 M sucrose or 0.5 M sodium chloride on a 

computerized version of the Labeled Magnitude Scale (Bartoshuk, 

Duffy, Fast, Green, Prutkin, and Snyder, 2003). Intensity ratings were 

greater for both test stimuli when preceded by a 30-sec water rinse 

compared to a 30-sec self-adaptation rinse. Further, the pattern of 

results was similar when effects of order were controlled. These 

findings, similar to findings obtained with traditional methods of 

stimulus delivery, support the operational validity of TASTE for studies 

of adaptation. This work was supported by NIH grants R01 DC004849- 

01 to MEF and R01 DC00271-16 to LEM 


PERCEIVED INTENSITY FUNCTIONS GENERATED UNDER 

SIMULATED FMRI SCANNING CONDITIONS 

Haase L.B. 1, Cerf-Ducastel B. 1, Mellinger C. 1, Jacobson A. 1, Murphy 

C. 2 1Psychology, San Diego State University, San Diego, CA; 

2Psychology, San Diego State University, University Of California, San 

Diego, San DIego, CA 

Currently, research on the psychophysics of taste has become 

increasingly important; e.g., for interpretation of functional MRI data. 

However, an important question is how slopes of functions relating 

perceived intensity to concentration of taste stimuli measured under 

conditions outside of the scanning environment will be related to slopes 

of intensity functions for stimuli presented under the severe constraints 

on stimulus delivery that apply in fMRI experiments. The current study 

investigated perceived intensity across a number of taste stimuli at 

various concentrations, in healthy young-adults, with a stimulation 

protocol adapted for fMRI scanning. Stimuli were presented at regular 

intervals in small boluses (.03ml) to minimize swallowing when the 

subject is lying on the back inside the scanner. Intensity was measured 

using Green´s Labeled Magnitude Scale. Slopes of intensity functions 

for stimuli presented in the simulated scanning conditions of the present 

study were compared to slopes from previous studies using the dorsal 

flow and "sip and spit" techniques. Results indicate that the slopes of 

intensity functions for Sucrose, NaCl, Caffeine, Saccharin, and MSG in 

the simulated scanning conditions were similar to the values for slopes 

from dorsal flow studies and generally lower than in studies done with 

the sip and spit method. Previous psychophysical taste research using 

the dorsal flow technique may be particularly useful for interpretation 

of future fMRI experiments. 

Supported by NIH Grant # AG04085 to Claire Murphy. 

79 


SUPERTASTING IS NOT EXPLAINED BY THE PTC/PROP 

GENE 

Bartoshuk L.M. 1, Davidson A. 2, Kidd J. 2, Kidd K.K. 2, Speed W. 3, 

Pakstis A. 2, Reed D. 4, Snyder D. 1, Duffy V.B. 5 1Surgery, Yale 

University, New Haven, CT; 2Genetics, Yale University School of 

Medicine, New Haven, CT; 3Genetics, Yale University, New Haven, CT; 

4Monell Chemical Senses Center, Philadelphia, PA; 5Dietetics 

Program, University of Connecticut, Storrs, CT 

An important gene (TAS2R38) contributes to PTC/PROP perception 

(Kim et al, 2003). Two common forms of this putative taste receptor are 

defined by single nucleotide polymorphisms that result in three amino 

acid substitutions: Pro49Ala, Ala262Val, and Val296Ile, leading to 

haplotypes PAV and AVI. The ancestral human haplotype is Proline- 

Alanine-Valine (PAV) which was associated with lower PTC 

thresholds (tasters); AVI (I=Isoleucine) was associated with higher PTC 

thresholds (nontasters). Subjects provided PROP thresholds (N=54), 

rated the bitterness of PROP (0.032-3.2 mM) with the general Labeled 

Magnitude Scale and were genotyped for the PTC/PROP gene (N=91). 

Threshold data corroborated those presented by Kim et al; PAV/PAV 

thresholds were lowest, AVI/AVI thresholds highest and PAV/AVI 

thresholds intermediate. However, suprathreshold functions showed 

that PAV/PAV tasters perceived significantly but only slightly more 

bitterness than did PAV/AVI tasters; AVI/AVI nontasters perceived the 

least bitterness. Of critical note, PAV/PAV tasters are not identical with 

supertasters defined by psychophysical criteria. Some of the factors (in 

addition to the PTC/PROP gene) likely to contribute to the perceived 

bitterness of PROP are density of fungiform papillae, other bitter genes 

and pathology. The distinction between medium and supertasters plays 

an important role in health outcomes related to oral perception. 

(NRICGP/USDA 2002-00788, DC00283, GM 57672). 


CHILDHOOD TOBACCO EXPOSURE INCREASES OBESITY 

RISK IN ADULT MEN 

Snyder D.J. 1, O'Malley S.S. 2, Mckee S. 2, Bartoshuk L.M. 1 1Surgery, 

Yale University, New Haven, CT; 2Psychiatry, Yale University, New 

Haven, CT 

Maternal smoking during pregnancy promotes childhood obesity, but 

its impact on adult body mass remains unclear. Notably, these findings 

fail to consider the role of tobacco use in the home, where chronic 

exposure throughout childhood may confer long-term health risk. Early 

tobacco exposure promotes childhood ear infections, which alter oral 

sensation by damaging the chorda tympani; for male supertasters of 

PROP (6-n-propylthiouracil), such changes may encourage fat intake 

and adult-onset obesity. Consistent with this model, we show that 

postnatal tobacco exposure correlates with increased body mass index 

(BMI) in adult men. Participants in a smoking cessation program 

(N=288) provided height, weight, family smoking history, and patterns 

of tobacco and alcohol use and abstinence. Tobacco exposure produced 

significant differences in men only; women were unaffected. Adult men 

raised in homes with 2+ smokers during ages 1-10 had higher BMIs 

than did men raised among fewer smokers; they were also more likely 

to be overweight. Although BMI often rises with smoking cessation, 

these men were willing to tolerate extreme gains leading to clinical 

obesity. Childhood exposure to maternal smoking contributed to higher 

rates of quit-related BMI gain, but prenatal exposure was unrelated to 

any adult BMI measure. These data suggest that postnatal tobacco 

exposure advances obesity risk in adult men by supporting pathologic 

changes in oral sensation. (Supported by the Transdisciplinary Tobacco 

Use Research Center at Yale and grants from NIDA/NCI (SSO), and 

NIDCD (LMB).)


THE INFLUENCE OF HEAD TRAUMA (HT), OTITIS MEDIA 

(OM), AND TONSILLECTOMY ON ORAL SENSATION, FAT 

ACCEPTANCE, AND BODY MASS INDEX (BMI) 

Chapo A. 1, Alex J. 2, Coelho D. 1, Duffy V.B. 3, Snyder D. 1, Bartoshuk L. 1 

1Surgery, Yale University, New Haven, CT; 2Otolaryngology, Lahey 

Clinic Medical Center, Burlington, MA; 3Dietetics, University of 

Connecticut, Storrs, CT 

Due to the close proximity of cranial nerve IX to the tonsillar bed, 

taste could be damaged by tonsillectomy. The present study explores 

oral sensation, food preferences, and BMI related to tonsillectomy and 

other taste-related pathology. Lecture attendees (n=674) reported 

weight, height, and pathology (OM, HT, and tonsillectomy) and rated 

remembered sensations, butterscotch candy sweetness, and acceptance 

of 26 foods on the general Labeled Magnitude Scale (gLMS). A 

statistically reliable group of 9 high-fat foods was positively associated 

with BMI. Females aged 25-65 who demonstrated proper use of the 

gLMS (most extreme light and sound greater than/equal to strong) were 

included and classified as follows: controls reported no pathology, 

“OM/HT” reported OM and/or HT (indicating VII loss), “TONs” 

reported tonsillectomies (indicating IX loss), and “COMBOs” reported 

OM and/or HT with tonsillectomy (indicating VII and IX loss). 

Compared to controls and TONs, COMBOs perceived less candy 

sweetness, suggesting taste loss; in those aged 40+, COMBOs liked fat 

foods more and had greater BMIs. OM/HTs perceived less sweetness 

than controls. In those aged 40+, OM/HTs tended to like fat foods more 

than controls but the two groups showed no differences in BMI. 

Summary: Damage to VII and IX may release inhibition on oral 

somatosensation; subsequent changes in fat acceptance may modulate 

obesity risk. Damage to VII alone may produce intermediate effects. 

(DC00283) 

307 Slide [ ] Taste Psychophysics 

GUSTATORY RESPONSES TO UNILATERAL 

GLOSSOPHARYNGEAL NERVE DAMAGE 

Pitovski D.Z. 1, Goins M. 1 1WFU Smell and Taste Center, Department 

of Otolaryngology, Wake Forest University, Winston-Salem, NC 

At our Wake Forest University Smell and Taste Center we have been 

referred several patients (in a six-month period) with the complaint of 

taste distortion following unilateral tonsillectomy. We report a patient 

that complains of taste distortion following a right tonsillectomy for 

unilateral tonsillar hypertrophy. After a complete clinical evaluation 

and taste testing it was found that the patient suffered an injury to the 

right lingual branch of the glossopharyngeal nerve. The close 

anatomical relationship between the palatine tonsil and lingual branch 

of the glossopharyngeal nerve makes the nerve vulnerable during 

tonsillectomy. This injury has caused the patient to suffer ageusia to the 

right posterior one-third of the tongue compensated by a contralateral 

phantogeusia (phantom taste) with clinical dysgeusia. The phantogeusia 

was abolished by application of anesthetic to the area where the 

phantom was perceived. We propose that the phantogeusia is the result 

of release-of-inhibition in the contralateral glossopharyngeal nerve. 

Taste distortion (including, phantogeusia and dysgeusia) after 

tonsillectomy is rarely reported as complication, but has a significant 

impact on quality of life. This preliminary study examines the taste 

distortion presence as a complication following glossopharyngeal nerve 

damage during tonsillectomy. 

80 

308 Slide [ ] Cortical Signal Processing 

FLEXIBILITY, NOT CONTENT, OF CUE REPRESENTATIONS 

IN ABL DEPENDS ON INPUT FROM OFC 

Schoenbaum G. 1, Saddoris M.P. 2, Gallagher M. 2 1Department of 

Anatomy and Neurobiology, University of Maryland at Baltimore, 

Baltimore, MD; 2Department of Psychological and Brain Sciences, 

Johns Hopkins University, Baltimore, MD 

Interactions between orbitofrontal cortex (OFC) and basolateral 

amygdala (ABL) are critical to the encoding and use of information 

regarding incentive value. We have reported that neurons in ABL 

develop differential firing to odor cues paired with appetive and 

aversive tastant outcomes. These differential responses reflect the 

acquired value of the cue and the predicted outcome. To assess the 

influence of input from OFC, we recorded from ABL neurons in rats 

with ipsilateral neurotoxic lesions of OFC as the rats were learning and 

reversing novel 2-odor discrimination problems. Correlates of these 

neurons were compared with those of ABL neurons recorded in rats 

with sham lesions. We compared activity on S+ and S- trials during 

odor sampling, responding and outcome presentation. We found that 

OFC lesions had little effect on the proportions of cue-selective neurons 

observed or on how selectivity emerged in these neurons with learning. 

Nor did the OFC lesions affect the proportion of the cue-selective 

neurons that also exhibited differential activity before and during 

outcome presentation. OFC lesions did, however cause a dramatic 

reduction in the flexibility of these representations after reversal. While 

53% of the cue-selective neurons reversed odor preference after 

reversal in intact rats, only 15% did so in rats with OFC lesions. These 

results suggest that although input from OFC may not be fundamental 

to the ability of ABL to represent cue value, this input does appear to be 

critical for the rapid flexibility of those representations, consistent with 

the deficit in reversal learning that is the hallmark of OFC lesions in 

rats and primates. Supported by K08-AG00882 and R01-DA015718 

(GS) and R01-MH60179 (MG).


BRAIN ACTIVATION PATTERN IN RESPONSE TO 

OLFACTORY RECOGNITION MEMORY 

Cerf-Ducastel B. 1, Chen M. 2, Abou E. 3, Haas L. 3, Murphy C. 1 

1Psychology, San Diego State University, San Diego, CA; 2University of 

California, San Diego, san diego, CA; 3San Diego State University, san 

Diego, CA 

Ten young subjects (age 20 to 25 y) participated in a functional 

Magnetic Resonance Imaging (fMRI) study with a 3T MR scanner. 

Before entering the scanner subjects were presented with 16 familiar 

odors. They then were scanned for 3 runs during which they were 

presented with words on a screen every 4 sec which were either names 

of odors previously presented (targets) or names of new odors (foils). 

Subjects responded by pressing either button 1 if they recognized the 

odor or button 2 if not. Each run alternated 4 ÒN´ periods containing 7 

targets and 2 foils (36 s) and 4 ÒFF´ periods with 7 foils and 2 targets 

(36 s). Data were processed with AFNI (Cox 1996) and compared ON 

and OFF periods, extracting regions that responded to cross-modal 

olfactory recognition memory. Group analysis showed that during the 

first run activated regions included right hippocampus, 

piriform/amygdalar area, superior temporal gyrus, anterior cingulate 

gyrus, inferior frontal/orbito frontal gyrus, superior/medial frontal 

gyrus, and bilateral parahippocampal gyrus, inferior parietal lobule, 

supramarginal gyrus, cerebellum, lingual/fusiform area, and 

middle/posterior cingulate gyrus. Region of interest analysis showed 

that degree of activation significantly decreased from run 1 to run 3 in 

the right hippocampus, fusiform and lingual gyrus, parahippocampal 

gyrus and middle frontal gyrus but not in other regions, suggesting that 

these regions sustain a specific function in olfactory recognition 

memory that attenuates as foils become more familiar with repeated 

presentation. Supported by NIH grant AG04085 to CM. 


CONTEXT DEPENDANT ACTIVITY IN PRIMARY 

OLFACTORY CORTEX OF HUMANS 

Sobel N. 1, Zelano C. 1, Mainland J. 1, Porter J.A. 1, Johnson B. 1, Bremner 

E. 1, Bensafi M. 1, Khan R. 1 1Neuroscience, University of California, 


Attentional modulation of neural activity patterns has been 

demonstrated in primary visual and auditory cortex. Similarly, activity 

in the rat olfactory bulb reflects non-odor cues that are merely 

associated with odor content, and activity in rat olfactory cortex 

reflects the motivational significance of an odor. To ask whether 

contextual modulation is evident in activity patterns of human primary 

olfactory cortex we used functional magnetic resonance imaging to 

measure sniff-induced neural activity in and out-of an olfactory context. 

Each trial of an event related design began with an auditory primer for 

"task detection" or "task inhalation". In "task detection" subjects took 

one sniff and determined whether an odorant was present or not. Odor 

was present on half of these trials. In "task inhalation" subjects also 

took one sniff, but knew in advance that an odor would never be 

present. Thus, the only difference between sniffs in "task inhalation", 

and the no-odor sniffs of "task detection" was that in the latter condition 

subjects were exploring for the presence of odor. Real-time 

measurement of nasal respiration assured sniffs were equal across 

conditions. Twelve subjects were scanned at 4T (2-shot T2* sensitive 

EPI, TR = 1000 ms, TE = 30 ms, flip angle = 20?, 64 x 64 voxel matrix, 

192 x 192 mm FOV, in-plane resolution = 3.5 mm, through-plane 

resolution = 3.5 mm). Activity in primary olfactory cortex was 

significantly higher when sniffing clean air in "task detection" than 

when sniffing the same content in "task inhalation" (p < .04). In other 

words, activity in human primary olfactory cortex was strongly 

dependant on task context. Supported by NSF. 

81 


INFORMATION CODING IN THE OLFACTORY SYSTEM 

Buck L. 1, Zou Z. 1 1Basic Sciences, Fred Hutchinson Cancer Research 

Center, Seattle, WA 

Odorants are detected in mice by 1000 different odorant receptors 

(ORs) that are expressed by olfactory sensory neurons in the nose. The 

ORs are used combinatorially to detect different odorants and encode 

their unique identities. To explore the mechanisms underlying odor 

perception, we asked how inputs derived from different mouse ORs are 

organized as signals travel from the nose to the olfactory bulb and then 

the olfactory cortex. In the nose, each sensory neuron expresses a single 

OR gene. Neurons with the same OR are dispersed in the nose, but their 

axons converge in a few glomeruli at two fixed locations in the bulb. 

The result is a stereotyped sensory map in which inputs from different 

ORs are segregated in different glomeruli and relay neurons. In the 

olfactory cortex, inputs from one OR are targeted to clusters of neurons 

at specific sites, creating a stereotyped map unrelated to that in the bulb. 

In contrast to the segregation of different OR inputs seen in both the 

nose and bulb, it appears that different OR inputs overlap extensively in 

the cortex and single neurons may receive combinatorial inputs from 

many different ORs. Using c-Fos as an indicator of neuronal activator, 

we found that different odorants elicit different, but partially 

overlapping, activation patterns in the cortex. The representation of 

each odorant is composed of a small subset of sparsely distributed 

neurons. Quantitative analysis of the odor representations suggests that 

cortical neurons may function as coincidence detectors that are 

activated only by correlated inputs from different ORs. 

312 Symposium [ ] Chemical Communication in Mammals: 

From Pheromones to Individual Recognition 

THE MAMMARY PHEROMONE OF THE RABBIT: IDENTITY, 

SOURCE, AND SOME FUNCTIONS 

Schaal B. 1, Coureaud G. 1, Moncomble A. 1, Langlois D. 2 1Centre des 

Sciences du Goût, CNRS, Dijon, France; 2UMRA, Inra, Dijon, France 

Mammalian females have evolved odor cues to guide their newborns 

to their mammae, whereas newborns have coevolved reliable means to 

respond to them efficiently. The domestic rabbit is a particularly 

suitable model to understand these cues because of the extremely 

sparing nature of maternal care enforcing nose-lead pups to 

instantaneously seize a nipple. Using a GC-olfaction assay on the 

volatiles of rabbit milk, an active compound was identified as 2methylbut-2-enal. 

It releases stereotypical searching and oral grasping 

in pups as effectively as milk itself. Its activity is concentrationdependent 

and qualitatively selective as 40 other odorants from milk, 

from rabbit secretions or chosen arbitrarily revealed ineffective. The 

compound qualifies as a pheromone in the sense defined by Beauchamp 

et al (1976) and Johnston (2000) for mammals: It triggers invariant 

responses of clear functional significance, generalizes across pups of 

various genetic and dietary backgrounds, and acts instantly as an 

unconditional stimulus in pups devoid of prior exposure with it. As it 

seems to be emitted de novo in the mammary tract, we named it 

'mammary pheromone' (MP). It is one of the key compounds of ejected 

milk as its concentration in milk correlates with behavioural activity. In 

more functional terms, the MP has a powerful activating impact on 

pups resting in the nest, and directs searching as efficiently as odor cues 

emitted on the abdominal surface by lactating does. This predisposed 

odour-behavior coupling will be discussed in the context of motheryoung 

communication and of adaptive development of offspring in 

mammals.



MAKING “SCENTS” OF OWNERSHIP 

Hurst J. 1 1Veterinary Clinical Science, University of Liverpool, Wirral, 

United Kingdom 

In order that a receiver can match information in a scent mark to an 

individual owner, the signal must provide stable and persistent 

information about the owner´s individual identity. In mice (Mus 

domesticus), two polymorphic gene complexes contribute to the scents 

that differ between individuals: the major histocompatibility complex 

(MHC) and the major urinary proteins (MUPs). These polymorphic and 

polygenic proteins are “hard-wired” in the genome and could provide 

stable ownership signals, while volatiles determined by developmental 

and environmental as well as genetic factors provide information on the 

current status of the owner. MHC-associated odours are important in 

promoting MHC-disassortative mate selection and kin recognition, but 

their contribution to individual identity signatures is unclear. Recent 

experiments reveal that individual MUP patterns are the basis of 

ownership signals in male competitive scent marks. Our current 

hypothesis, of an associative mechanism, attempts to bring together the 

different contributions made by MHC and MUPs. Volatile components 

perceived at a distance induce investigation through contact. The 

receiver then learns an association between the variable volatile 

signature detected through the main olfactory system and the involatile 

MUP signature detected via the vomeronasal system. Plasticity in this 

association means that changes in volatile signatures can be reassociated 

with stable involatile signatures during contact investigation. 

This permits rapid and distant identification when volatile signatures 

are familiar, together with a reliable signature of identity even when 

status or environment changes. Funded by BBSRC, UK 



WHY MUSTH (AND OTHER) ELEPHANTS USE 

PHEROMONES 

Rasmussen L.E. 1, Greenwood D.R. 2 1OGI School of Science & 

Engineering, OHSU, Beaverton, OR; 2Gene Technologies, 

HortResearch, Auckland, New Zealand 

In the wild Elephas maximus and Loxodonta africana societies are 

generally stable and often resilient, two attributes reinforced by 

longevity, multigenerational matriarchal families, and multimodal 

signaling between individuals. In Asian elephants successful life 

strategies and complex behaviors are interlocked with an extensive 

chemical communication system. Initially, well-defined behaviors of 

wild and captive elephants formed the foundation for our investigation 

of olfactory communication. Two chemically identified pheromones, 

(Z)-7-dodecenyl acetate, released by preovulatory females, and 

frontalin, released by older adult males in musth, elicit distinctive, 

quantitatively measurable and statistically valid sex- and sexual-statespecific 

behaviors. The vast size and clearly spatially and functionally 

differentiated anatomical interrelationships of the main olfactory and 

vomeronasal organ systems not only allow the investigation of systems 

interplay, but effectively slow down individual biochemical events as 

temporally discrete steps, allowing such biochemical olfactory events to 

be correlated in real time with behavioral actions. The partially 

elucidated pathways for pheromone transport from trunk tip to sensory 

epithelia involving specific binding proteins will be demonstrated using 

concurrent biochemical and behavioral experiments, and will include 

data on protein-pheromone interactions and kinetic analyses, 

demonstrating that our Asian elephant model of vertebrate olfaction is 

an attractive experimental system with which to study distinctive steps, 

especially periceptive events, in discrete time. 

82 



INDIVIDUAL RECOGNITION: SIGNALS, BEHAVIOR AND 

NEURAL MECHANISMS 

Johnston R.E. 1 1Psychology, Cornell University, Ithaca, NY 

Recognition of individuals is essential for many types of social 

behavior and reproductive fitness in vertebrates. The cues for such 

recognition are complex and multi-dimensional; odor cues for 

individual recognition consist of complex mixtures whose proportions 

vary across individuals (mosaic signals). Since other individuals can 

have great emotional significance, individually distinctive signals can 

have powerful influences on behavior (e.g., fear specific to a familiar 

opponent). Hamsters (Mesocricetus auratus) use at least 4 sources of 

body odor for recognition of individuals and they have integrated, 

multi-component memories of such individuals. They also have 

extraordinary abilities to analyze scent over-marks and to determine 

which individual´s scent is on top of the other; they use this information 

to evaluate the vigor and quality of potential mates. At the neural level 

of analysis, both the main olfactory and vomeronasal systems 

contribute to discrimination of individuals by odors. Brain imaging 

studies using immediate early genes as markers for cell activity indicate 

circuits that are probably involved in recognition, memory, and 

appropriate emotional responses to familiar individuals (specifically, 

winners of fights with the subjects). These areas include parts of the 

hippocampus (dorsal CA1 area and subiculum), other para-hippocampal 

areas, and the basolateral amygdala. This model system provides insight 

into the functions of higher-order olfactory processing and areas of the 

brain involved in social behavior. 

Supported by NIH grant 5R01 MH58001-01A1. 

316 Poster [ ] Taste: Animal Behavior 

MICROSTRUCTURAL ANALYSIS OF LICKING IN THE 

FORMATION AND EXTINCTION OF A CONDITIONED 

TASTE AVERSION 

Baird J.P. 1, St. John S.J. 2, Nguyen E.A. 1 1Psychology, Amherst College, 

Amherst, MA; 2Reed College, Portland, OR 

LiCl (ip) paired with intraoral sucrose causes sucrose taste reactivity 

to shift to a profile that resembles aversive intraoral QHCl. We used 

lick microstructure analysis to assess changes in oromotor activity 

under conditions that may better approximate natural toxin exposure. 

Water-deprived rats were trained to access dh2o 15 min/day from a 

bottle connected to a lickometer. On days 1,3,&5 0.12M LiCl (8 rats) or 

0.12M NaCl (8 rats) solution replaced dh2o. On days 7,9,&11 only 

0.12M NaCl replaced dh2o. A 2nd study used 0.24M NaCl instead of 

0.12M NaCl. On the 1st LiCl day rats avidly drank LiCl for 3 min: 1st 

min lick rates and mean burst durations were comparable to NaCl 

controls. As LiCl licking progressed, ingestion rate slowed significantly 

by the 4th-6th minute vs. controls. On subsequent LiCl tests, intake, 

initial rate, burst duration, ingestion rate & lick volume were 

significantly reduced. However, burst count was significantly increased. 

In rats ingesting NaCl after LiCl, intake, initial lick rate (except .24M 

NaCl), ingestion rate, burst duration & lick volume remained 

significantly reduced relative to controls, and burst count remained 

increased by at least 72%. Over remaining NaCl tests effects reversed 

and almost all differences were extinguished by the last NaCl day. 

These effects of LiCl parallel microstructural responses to 0.2mM 

QHCl, and shifts in taste reactivity after CTA formation. The generality 

of these results across two paradigms supports the notion that CTA´s 

can affect hedonic evaluation of tastants. The construct validity for both 

techniques as useful tools in the measurement of hedonic gustatory 

processes is also supported. Supported by a Mellon-8 grant to JPB.


D-CYCLOSERINE POTENTIATES SHORT-DELAY, BUT NOT 

LONG-DELAY, CONDITIONED TASTE AVERSION. 

Davenport R.A. 1, Houpt T.A. 1 1Biological Sciences, Florida State 

University, Tallahassee, FL 

D-Cycloserine (DCS) is a partial glycine agonist at the NMDA 

glutamate receptor site, and has been shown to facilitate both 

declarative and non-declarative memory tasks. In order to determine if 

DCS enhances conditioned taste aversion (CTA) learning, we 

administered DCS before the pairing of saccharin intake and LiCl 

injection and measured expression with 2-bottle tests. 

Water-deprived rats were injected with DCS (15mg/kg i.p.) 15 min 

prior to 10-min access to 0.125% saccharin. Rats were injected with 

LiCl (19mg/kg i.p.) 25 or 60 min after DCS. Controls were injected 

with saline in place of DCS, or saline in place of LiCl. One day after 

conditioning, rats were given 24-h, 2-bottle preference tests for 14 days. 

Daily saccharin preference was calculated as saccharin intake over total 

intake. 

Control rats showed no CTA when saccharin was paired with saline 

(pref: 0.9 ± 0.04), and only a moderate CTA after LiCl injection in the 

absence of DCS (pref: 0.4 ± 0.1, p < 0.01 vs. saline). In the presence of 

DCS, rats showed a stronger aversion after LiCl at 25 min (pref: 0.06 ± 

0.02, p < 0.05 vs. LiCl alone), but the same aversion after LiCl at 60 

min (pref: 0.32 ± 0.1). 

We conclude that DCS enhances a CTA but is dependent on the 

timing of both the gustatory stimulus and the toxin, such that DCS 

potentiated short-delay but not long-delay pairing of saccharin and 

LiCl. This difference may be due to the short-half life of DCS, or it may 

reflect different roles for NMDA neurotransmission in gustatory and 

toxin processing. Current studies are probing different time points with 

DCS to distinguish these possibilities. Supported by an FSU 

Neuroscience Fellowship and NIDCD 03198. 

83 


DIFFERENCES IN GUSTATORY BEHAVIOR BETWEEN 

C57BL/6J AND DBA/2J INBRED MICE 

Raghow S. 1, Boughter J.D. 1, Nelson T.M. 2, St. John S.J. 3, Munger S.D. 2 

1Anatomy & Neurobiology, University of Tennessee, Memphis, TN; 

2Anatomy and Neurobiology, University of Maryland at Baltimore, 

Baltimore, MD; 3Reed College, Portland, OR 

The commonly used C57BL/6J (B6) and DBA/2J (D2) strains of 

inbred mice are among the strains included in the public and private 

genome sequencing projects and, given the availability of BXD 

recombinant inbred (RI) strains, provide an extremely desirable model 

for genetic studies. B6 and D2 mice have been shown to differ in terms 

of intake behavior to taste stimuli of different qualities, illustrating the 

potential of the BXD RI set for mapping QTLs influencing taste 

sensitivity. However, 24- or 48-hr intake tests are generally confounded 

by non-gustatory or post-ingestive factors such as olfactory cues, 

caloric load, and toxicity. We examined gustatory behavior, especially 

to an array of stimuli characterized as bitter or aversive, in B6 and D2 

mice using both intake and brief-access tests. Robust strain differences 

in sensitivity for bitter stimuli QHCl, PROP and RUA were found using 

both assays. However, the strains did not differ for cycloheximide, 

strychnine, or MgCl2 in the brief-access test. We also failed to detect a 

strain difference for salts using either assay. We also developed a 4-day, 

high-throughput screen for bitter taste sensitivity. B6, D2, and BXD F1 

and F2 intercross mice were tested with two concentrations each of 

denatonium benzoate, PROP, and QHCl. Mice were also assessed for 

additional non-gustatory phenotypes, including water lick rate, water 

consumption, latency to first lick and overall performance in the task. 

B6 and D2 mice significantly differed in taste sensitivity for PROP and 

QHCl. However, sensitivity to PROP and QHCL were not correlated (r 

= 0.08) in 126 F2 mice, demonstrating independence of these 

phenotypes. Supported by NIDCD: DC005786(SDM), 

DC004935(JDB). 


GAPING TO QUININE IN GLOSSOPHARYNGEAL NERVE- 

TRANSECTED RATS AFTER POSTSURGICAL TASTE 

AVERSION CONDITIONING 

Bayevsky A. 1, Colbert C.L. 1, Garcea M. 1, Newth A. 1, Spector A.C. 1 

1Psychology Department, University of Florida, Gainesville, FL 

Glossopharyngeal nerve transection (GLX) in rats has been shown to 

significantly reduce gaping, a stereotypical oromotor rejection behavior, 

in response to intraoral quinine hydrochloride (Q) infusion. We 

examined whether gaping to Q could be increased by a conditioned 

taste aversion (CTA) to this stimulus in GLX rats. Rats had intraoral 

cannulae implanted and either received sham surgery (SHAM) or GLX. 

After habituation to the test chamber, animals were infused with 0.3 M 

sucrose for 3 minutes (1 mL/min) on 3 consecutive days, followed by 

0.6 mM Q infusion, the latter of which preceded an injection (inj) of 

LiCl or NaCl (2.0 mEq/Kg). The rats were videorecorded and this 4-day 

cycle was repeated 3 more times with no injections given after the last 

Q infusion (test day). The first 30 s of the test-day Q infusion were 

scored for gapes adjusted for unscorable periods. The LiCl-inj SHAM 

(n=7) and GLX (n=9) groups gaped significantly more to Q compared 

with the NaCl-inj GLX (n=7) rats and did not differ from each other. 

Gaping in the NaCl-inj SHAM (n=8) rats fell between these two 

extremes and only significantly differed from that in the LiCl-inj GLX 

group. The lack of an expected significant difference in gapes between 

the 2 NaCl-inj groups could be due to repeated stimulus exposure 

effects. We are scoring the first Q infusion to evaluate this and to allow 

us to conduct within-subjects analyses. At present, these findings 

suggest that a CTA can increase gaping to Q in GLX rats as has been 

previously shown for sucrose. Supported by NIH R01-DC01628.


TASTE PREFERENCE AND TASTE BUDS MAINTENANCE 

AFTER UNILATERAL LINGUAL DENERVATION IN RATS. 

Lee J. 1, Kim Y. 1, Moon Y. 2, Jahng J. 3 1Oral & Maxillofacial Surgery, 

Seoul National University College of Dentistry, Seoul, South Korea; 

2Biology, Catholic University College of Medicine, Seoul, South Korea; 

3Yonsei University College of Medicine, Seoul, South Korea 

Intact gustatory nerve supply appears to be required for the 

maintenance of taste buds, and unilateral transection of gustatory nerve 

results in reduced number of taste papillae with degeneration and 

disappearance of taste buds ipsilateral to the surgical side. We 

examined the effects of unilateral lingual nerve transection on taste 

function as well as on the maintenance of taste buds. Male Sprague- 

Dawley rats weighing 250-300g received unilateral transection of 

lingual nerve, subjected to the preference test for various taste solutions 

(0.1M NaCl, 0.1M sucrose, 0.01M QHCl, or 0.01M HCl) with two 

bottle test paradigm at 2, 4, 6, or 8 weeks after the operation. Water and 

each test solution bottle were supplied for 48 h at each test with one 

change of the bottle position at 24 h. The preference score for salty, 

sweet or sour taste, but not for bitter taste, tended to be higher in the 

operated rats without statistical significance, compared to the sham rats. 

Overall pattern of the preference scores was not changed by time after 

operation. These results suggest that unilateral damage of lingual nerve 

may not significantly affect taste function of the subject. In order to 

examine the morphologic changes of tongue, number of fungi form 

papillae on the denervated side was counted in comparison with the 

intact side. Time course of apoptotic death of taste cells in the foliate 

and vallate papillae was examined as well. Supported by the Korea 

Health R & D Project (JHL), KISTEP(JWJ). 

321 Poster [ ] Taste: Peripheral Connectivity 

ULTRASTRUCTURE OF MORPHOLOGICALLY IDENTIFIED 

CHORDA TYMPANI AXONS IN THE NUCLEUS OF THE 

SOLITARY TRACT IN DEVELOPMENTALLY SODIUM- 

RESTRICTED AND CONTROL RATS 

May O.L. 1, Erisir A. 1, Hill D.L. 1 1Psychology, University of Virginia, 

Charlottesville, VA 

Dietary sodium restriction during a critical period in gestation results 

in specific, yet profound morphological changes in the dorsal zone of 

the chorda tympani nerve terminal field in the adult rat nucleus of the 

solitary tract. Specifically, there is an approximate two-fold increase in 

volume of the dorsal zone of the terminal field in sodium-restricted rats 

compared to controls. In order to better characterize this plasticity, we 

examined the ultrastructure of terminals identified by way of bulklabeling 

the chorda tympani nerve with biotinylated dextran and 

visualizing with DAB. Quantitative measurements in the dorsal zone of 

the chorda tympani field in both sodium-restricted and control rats 

included volumetric density of labeled synapses and synapsing 

frequency of axons. Preliminary evidence indicates that there is over a 

four-fold increase in the density of chorda tympani terminals in the 

dorsal region in restricted rats compared to controls. However, there 

was not a significant increase in synapse density along any given axon, 

suggesting that elaboration of chorda tympani input to this region 

occurs by addition of new axonal arbors. Furthermore, there is a 

conspicuous qualitative difference in the morphology of synaptic 

terminals in sodium-restricted rats in that their profiles are interrupted 

by finger-like protrusions of dendritic spines. These results indicate a 

process of synaptic remodeling as well as an elaboration of connectivity 

occurs as a result of developmental sodium restriction. Supported by 

NIH grants DC00407 and F31 DC06332 

84 


GUSTATORY NERVE TERMINAL FIELDS IN RATS 

RECOVERED FROM EARLY DEVELOPMENTAL SODIUM 

RESTRICTION. 

Mangold J.E. 1, Hill D.L. 1 1Psychology, University of Virginia, 

Charlottesville, VA 

A critical period for chorda tympani (CT) terminal field development 

is from embryonic day 3 (E3) to E12. When pregnant rats are fed a lowsodium 

diet during this period, the CT terminal field in their offspring 

(E3-E12 restricted) is enlarged compared to controls. Similarly, rats 

raised on a sodium-restricted diet from E3 to postnatal day 28 and then 

fed a sodium-replete diet for at least a month (P28 recovered) also have 

CT terminal fields that are large. To determine the interactions among 

the CT, GSP and IX terminal fields in controls, E3-E12 restricted, and 

P28 recovered rats, we used a triple fluorescent labeling procedure. In 

control rats, the IXth field is the most dorsal of the three fields and 

extends ventrally into the dorsal-most zone of the GSP. The CT field 

overlaps much of the GSP field, but has no overlap with the IXth field. 

In E3-E12 sodium restricted rats, the IXth field is approximately 3X 

greater than that in controls and extends medio-laterally and ventrally, 

well into the CT field. Both the GSP and CT fields are significantly 

larger than controls. P28 recovered rats had similar alterations of all 

three fields; however, they were not as dramatic as in E3-E12 restricted 

rats. Therefore, a very early period of dietary sodium restriction (E3- 

E12) that precedes the development of peripheral gustatory structures 

produces the most widespread effects on the development of gustatory 

afferents in the NTS. These results also suggest a greater functional 

convergence in the gustatory brainstem and behavioral consequences 

for sodium restriction during development. Supported by grant 00407. 


ISOFORMS OF THE SYNAPTIC VESICLE PROTEIN SV2 

HAVE DIFFERENT LOCATIONS IN THE RAT 

CIRCUMVALLATE GUSTATORY TISSUE 

Nelson G.M. 1 1Neurobiology, University of Alabama at Birmingham, 

Birmingham, AL 

SV2, a 12-transmembrane protein which may function as a calcium 

regulator in neurotransmission and a component of the intravesicular 

matrix, has three identified isoforms, A, B, and C. Presynaptic size 

vesicles are present in the gustatory system in primary afferent nerve 

fibers receiving synapses from taste cells, peptidergic intragemmal 

nerve fibers, and taste cells. Two color fluorescent microscopy of fixed 

rat tongue tissue sections is labeled with various SV2 antibodies. A 

general SV2 antibody labels most nerve fibers, including intragemmal, 

some perigemmal, peri-apical pore, basal plexus, and the sub-epithelial 

network of nerve fibers. SV2B has a very restricted pattern suggestive 

of location in taste cells, especially in taste buds in the lower 

circumvallate crypt. SV2C labels a smaller group of intragemmal, 

perigemmal, and basal plexus fibers than the general SV2 antibody. The 

SV2 general positive fibers are included in the population of fibers 

which label with PGP 9.5. Most SV2B and C positive structures 

colocalize with PGP-positive structures. In contrast, a few intragemmal 

fibers labeled with either the general SV2 or SV2B antibody appear to 

colocalize or oppose gustducin-positive taste cells. These results 

indicate that the antibodies to various SV2 isoforms may be a tool to 

differentiate various pools of small clear vesicles within the gustatory 

system. SV2-positive nerve fibers are a subset of the PGP-positive 

fibers and may identify synaptic sites between some nerve fibers and 

taste cells. Supported by NIDCD 00166.


SYNAPTOPHYSIN-LIKE IMMUNOREACTIVITY IN 

CIRCUMVALLATE PAPILLAE OF THE RAT AND MOUSE 

Schmidt K.C. 1, Yang R. 2, Kinnamon J.C. 3 1Biological Sciences, 

University of Denver, Denver, CO; 2University of Denver, Denver, CO; 

3Biology, University of Denver, Denver, CO 

Synaptophysin is an abundant protein in the CNS that is found in the 

membranes of synaptic vesicles. Synaptophysin is thought to play a role 

in the regulation of SNARE formation during synaptic transmission 

through its interactions with other proteins of the synaptic vesicle cycle, 

namely binding with VAMP/synaptobrevin. We postulate that 

synaptophysin is associated with the synaptic vesicles at taste cell 

synapses. Our preliminary results indicate that subsets of taste cells of 

the circumvallate papillae of both the rat and mouse display 

synaptophysin-like immunoreactivity (LIR). The immunoreactive cells 

are slender and span the entire length of the taste bud from the basal 

lamina to the taste pore. In the rat, nerve processes exiting the taste 

buds are also immunoreactive. Synaptophysin-LIR does not appear to 

colocalize with IP3R3-LIR, but does appear to colocalize with a subset 

of PGP 9.5 (protein gene product 9.5) immunoreactive cells. The 

elucidation of proteins such as synaptophysin involved in the synaptic 

vesicle cycle in taste cells may prove useful in determining how taste 

cells transmit information. Supported by NIH grants DC00285 and 

DC00244. 


IMMUNOCYTOCHEMICAL ANALYSIS OF SYNTAXIN IN 

RAT CIRCUMVALLATE TASTE BUDS 

Yang R. 1, Thomas S. 1, Kinnamon J.C. 1 1Biological Sciences, University 

of Denver, Denver, CO 

The SNARE proteins syntaxin, SNAP-25, and synaptobrevin all play 

key roles during Ca2+ dependent exocytosis in the CNS. We 

hypothesize that taste cell synapses utilize the same protein machinery 

as used by synapses in the CNS. Our previous studies have shown that 

taste cells with synapses display SNAP-25- and synaptobrevin-like 

immunoreactivity (LIR) (Yang et al., 2000; Yang et al., in press). At 

present, we are studying the presynaptic membrane protein, syntaxin, in 

rat circumvallate taste buds. Our current results indicate that syntaxin is 

present in a subset of taste cells and nerve processes in taste buds. 

Approximately 15% of the taste cells in a taste bud display cytoplasmic 

syntaxin-LIR and a smaller subset of taste cells also show punctate 

staining in the cytoplasm. Syntaxin-LIR colocalizes with SNAP-25- and 

synaptobrevin-LIR in a small subset of taste cells and most nerve 

processes. Approximately 11% of the syntaxin-LIR cells colocalize 

with PLCβ2-LIR cells. However, only about 4% of the PLCβ2-LIR 

cells also display syntaxin-LIR. DAB immunoelectron microscopy 

reveals that syntaxin-LIR is present in both type II and III taste cells. 

Type II taste cells display punctate syntaxin-LIR at Golgi bodies, while 

type III taste cells show cytoplasmic syntaxin-LIR. All of the synapses 

associated with syntaxin-LIR taste cells are from type III cells onto 

nerve processes. These results support the notion that taste cell synapses 

are similar to synapses of the CNS. Supported by NIH grant DC00285. 

85 


TASTE BUDS AND SURROUNDING FIBERS ARE 

IMMUNOREACTIVE FOR THE IONOTROPIC ATP 

RECEPTOR P2X7 

Stone L.M. 1, Kinnamon S.C. 1 1Biomedical Sciences, Colorado State 

University, Fort Collins, CO 

Processing of taste information probably involves intercellular 

communication within the taste bud as well as communication between 

individual taste cells and innervating nerve fibers. 

Immunocytochemical studies of transmitter proteins and receptors 

suggest that several neurotransmitter pathways are used by taste buds. 

Recent evidence suggests a role for ATP and its receptors in taste bud 

function (Bo et al., 1999; Y.V. Kim et al., 2000; Baryshnikov et al., 

2003). Further, physiological studies suggest taste cell responses to 

ATP involve metabotropic (P2Y-like) receptors. The current study was 

done to determine if ionotropic ATP receptors also are present on taste 

cells. Tongues from transgenic mice expressing GFP under the control 

of the α-gustducin promoter were examined for the presence of P2X7 

immunoreactivity. We found that P2X7 immunoreactivity includes taste 

cells as well as nerve fibers in and around taste buds. P2X7 occurs both 

in cells that express α-gustducin and in taste cells that lack the G 

protein. In conclusion, taste cells may signal to one another by both 

metabotropic and ionotropic ATP receptors. Supported by DC00766 


RECOVERY OF GURMARIN-SENSITIVE NEURAL 

RESPONSES AND EXPRESSION OF T1R3 AND GUSTDUCIN 

IN FUNGIFORM PAPILLAE AFTER CRUSH OF THE MOUSE 

CHORDA TYMPANI 

Yasumatsu K. 1, Shigemura N. 1, Shigeoka Y. 1, Ninomiya Y. 1 1Oral 

Neuroscience, Kyushu University, Fukuoka, Japan 

Gurmarin is known to be a peptide that selectively inhibits responses 

to sweet compounds in the chorda tympani nerve (CT) in C57BL mice. 

The peptide, however, suppresses only about half of the response to 

sucrose, indicating existence of both gurmarin-sensitive (GS) and - 

insensitive (GI) response components in the CT. In the present study, 

recovery of taste responses and reappearance of taste receptor cells 

were studied by examining GS of the CT responses and expression of 

T1R3 and gustducin in fungiform papillae. It was reported that T1R3 

contributes responses to sucrose, saccharin and other artificial 

sweeteners in the CT. At about 2 weeks after the nerve crush, although 

no significant responses to taste stimuli were observed in the CT, in situ 

hybridization analysis demonstrated that T1R3 and gustducin expressed 

in subsets of taste bud cells. At about 3 weeks after the CT crush, 

responses to sweet compounds reappeared and the threshold of sucrose 

was higher than that shown by intact CT. After more than a month, the 

CT showed GS comparable with those shown by intact animals. These 

data suggest that the molecules related to taste transduction might 

express in taste receptor cells prior to their contact with regenerated 

taste axons.


THE NEURAL ISOFORM OF TRYPTOPHAN HYDROXYLASE 

IS LOCALIZED TO TASTE BUD CELLS 

Cao J. 1, Huang L. 1, Brand J. 1 1Monell Chemical Senses Center, 


Taste receptor cells are epithelial in origin and form synaptic contact 

with innervating sensory nerves. The identification of the 

neurotransmitter(s) in these cells has, however, not been absolutely 

determined. While a number of studies implicate serotonin as a 

candidate neurotransmitter, evidence of its synthetic pathway in taste 

receptor cells is incomplete. In the current study, RT-PCR identified 

the neural isoform of tryptophan hyroxylase (TPH2) in rat foliate and 

vallate isolated taste buds and single taste bud cells (TBC). Sequencing 

of 666 bp near the 3´-end of the taste TPH2 showed this product to have 

99% identity with rat brain TPH2. The peripheral isoform, TPH1, could 

not be detected by RT-PCR in taste tissue, but was detected in brain 

cDNA, used as a positive control. Of 12 TBC wherein the synaptic 

marker, syntaxin, was detected by RT-PCR, TPH2, but not TPH1, was 

detected in 10 of these cells, and T1R3 detected in 6. 

Immunocytochemistry localized TPH2 to a subset of taste bud cells 

located within the main body of the bud. No staining was seen in the 

basal region nor in the perigemmal cells. The results support a role for 

serotonin as a neurotransmitter in taste receptor cells. 

Supported in part by a grant to JGB from the Department of Veterans 

Affairs, and by NIH DC05154 to L.H. 


TASTE BUDS RELEASE 5HT WHEN DEPOLARIZED 

Huang Y.J. 1, Lu K.S. 1, Roper S.D. 2 1Physiology & Biophysics, 

University of Miami, Miami, FL; 2Physiology & Biophysics and 

Neuroscience Program, University of Miami, Miami, FL 

Serotonin (5HT) is implicated as a neurotransmitter or 

neuromodulator in taste buds but to date there has been no direct 

evidence for its release from taste cells. Using a CHO/biosensor cell, 

we tested whether isolated mouse vallate taste buds release 5HT in 

response to stimulation. Pilot studies confirmed that CHO cells, stably 

transfected with 5HT2c receptors (Berg et al, Molec Pharmacol, 1994) 

and loaded with the Ca2+ -sensitive dye, Fura2, to assay responses, were 

exquisitely sensitive to 5HT (threshold ~3 nM). These "CHO/biosensor 

cells" did not respond to bath-applied KCl (50-100 mM) nor to 

cycloheximide (100 µM), a bitter taste stimulus. We confirmed that 

5HT-responses in CHO/biosensor cells were reversibly inhibited by 

mianserin (1-10 nM), a 5HT2c antagonist. We isolated taste buds from 

mouse vallate papillae and loaded them with Fura2 to verify that taste 

cells responded to KCl depolarization (50-100 mM). Finally, to test 

whether stimulated taste buds released 5HT, we isolated individual taste 

buds and plated them on a glass coverslip in a shallow recording 

chamber. Taste buds were approached with a Fura2-loaded 

CHO/biosensor cell held onto a fire-polished micropipette by gentle 

suction. Bath-applied KCl elicited responses in the CHO/biosensor cell 

when it was positioned against a taste bud. Applying buffer did not 

elicit responses. Furthermore, moving the CHO/biosensor away from 

the taste bud abolished responses. These data suggest that when they 

are depolarized, isolated taste buds release 5HT. Supported by DC 6077 

and DC00374 (SDR). 

86 


ANALYSIS OF A HUMAN FUNGIFORM PAPILLAE CDNA 

LIBRARY AND IDENTIFICATION OF TASTE-RELATED 

GENES 

Rossier O. 1, Cao J. 2, Huque T. 2, Spielman A.I. 3, Feldman R.S. 4, 

Medrano J.F. 5, Brand J.G. 2, Le Coutre J. 1 1Nestlé Research Center, 

Lausanne, Switzerland; 2Monell Chemical Senses Center, Philadelphia, 

PA; 3College of Dentistry, New York University, New York, NY; 4Dental 

Medicine, V.A. Medical Center, Philadelphia, PA; 5Department of 

Animal Science, University of California, Davis, CA 

Various genes related to early events in human gustation have 

recently been discovered, yet a thorough understanding of taste 

transduction is hampered by gaps in our knowledge of the signaling 

chain. As a first step toward gaining additional insight, the expression 

specificity of genes in human taste tissue needs to be determined. To 

this end, a fungiform papillae cDNA library has been generated and 

analyzed. For validation of the library, taste-related gene probes were 

used to detect known molecules. Subsequently, DNA sequence analysis 

was performed to identify further candidates. Of 987 clones sequenced, 

clustering results in 288 contigs. Comparison of these contigs with 

genomic databases reveals that 207 contigs (71.9%) match known 

genes, 16 (5.6%) match hypothetical genes, 8 (2.8%) match repetitive 

sequences and 57 (19.8%) have no or low similarity to annotated genes. 

The results indicate that despite a high level of redundancy, this human 

fungiform cDNA library contains specific taste markers and is valuable 

for investigation of both known and novel taste-related genes. 

331 Poster [ ] Human Olfaction: Pathology 

OLFACTORY FUNCTIONS AND VOLUMES OF 

ORBITOFRONTAL AND LIMBIC REGIONS IN 

SCHIZOPHRENIA 

Rupp C.I. 1, Fleischhacker W.W. 1, Kemmler G. 1, Kremser C. 2, Bilder 

R.M. 3, Mechtcheriakov S. 1, Szeszko P.R. 4, Walch T. 1, Scholtz A.W. 5, 

Klimbacher M. 1, Maier C. 1, Albrecht G. 1, Lechner T. 1, Felber S. 2, 

Hinterhuber H. 1 1University Clinics of Psychiatry Innsbruck, Innsbruck, 

Austria; 2University Clinics of Magnetic Resonance Imaging Innsbruck, 

Innsbruck, Austria; 3Geffen School of Medicine at UCLA, Los Angeles, 

CA; 4Zucker Hillside Hospital, Glen Oaks, NY; 5University Clinics of 

Otorhinolaryngology Innsbruck, Innsbruck, Austria 

Olfactory deficits in schizophrenia have been widely reported. These 

deficits have been hypothesized to be associated with abnormalities in 

prefrontal (orbitofrontal) and/or mesiotemporal brain regions. No study 

investigated this structure-function relationship using MR-imaging. We 

examined the relationship between olfactory functions and volumes of 

limbic (hippocampus/amygdala) and orbitofrontal brain regions in 

young men with schizophrenia and healthy subjects, matched for sex 

and age. Unirhinal assessment of olfactory measures included main 

functions (threshold, discrimination, identification) and odor 

judgements (intensity, familiarity, edibility, pleasantness). Patients 

performed bilaterally more poorly than controls in the threshold, 

discrimination and identification tasks, as well as on several odor 

judgement measures. Compared with controls patients showed bilateral 

smaller hippocampus and amygdala volumes. In patients, smaller 

volumes of the hippocampus were significantly correlated with poorer 

discrimination performance. Our results corroborate and extend 

previous findings of olfactory deficits as well as limbic structure 

volume reduction in schizophrenia, and suggest that olfactory deficits, 

namely impairments in discrimination, are associated with 

morphometric abnormalities in the hippocampus. 

Supported by OENB (no. 6576)

332 Slide [ ] Human Olfaction: Pathology 

DIMINISHED POSTERIOR NASAL VOLUMES IN MALE 

PATIENTS WITH SCHIZOPHRENIA 

Roalf D.R. 1, Turetsky B.I. 2, Balderston C.C. 1, Gur R.E. 1, Moberg P.J. 2 

1Schizophrenia Research Center, Department of Psychiatry, University 

of Pennsylvania, Philadelphia, PA; 2Schizophrenia Research Center, 

Department of Psychiatry & Smell & Taste Center, Department of 

Otorhinolaryngology:, University of Pennsylvania, Philadelphia, PA 

Background: Gross midline abnormalities such as cleft palate and 

cavum septum pelucidum, impairments in olfactory ability and to a 

lesser degree subtle craniofacial dysmorphogenesis are considered 

characteristics of schizophrenia. Due to concordant development of the 

oral cavity, olfactory structures, and ventral forebrain, we hypothesized 

that structural abnormalities of the nasal cavity might represent diseaseassociated 

markers of embryological dysmorphogenesis. 

Method: A measurement of nasal volume was acquired by acoustic 

rhinometry for 56 schizophrenia patients (44 men, 12 women) and 37 

healthy controls (24 men, 13 women). Nasal volume was segmented 

into three areas: Total (0.0-5.5cm), Anterior (0.0-3.5cm) and Posterior 

(3.5-5.5cm). 

Results: An overall MANOVA demonstrated a significant diagnosis 

by sex by nasal compartment interaction (F[2,172]=2.92, p=.05). 

Decomposition of this interaction revealed that male patients had 

significantly smaller left (F[2,126]= 6.26, p0.05 on Student's twotailed 

t test. Mean UPSIT score for controls was 33.5 and ET 32.2 

which is not significantly different. For IPD the mean score was 18.1 

which is significantly different from controls and ET. OERP showed no 

Difference for P2 latency between controls and ET patients (mean 

latency 628.5ms and 641.3ms respectively). In 21 PD patients the 

evoked response was absent. In the remaining 33 the mean latency was 

962ms which is significantly prolonged compared to controls and ET. 

In all three groups amplitude measurements did not differ significantly. 

A normosmic patient with tremor is more likely to have ET than IPD 

while someone with tremor and impaired olfaction may have IPD or 

related syndrome. 


MEMORY FOR EMOTIONAL AND NEUTRAL ODORS AND 

AMYGDALA ELECTROPHYSIOLOGICAL RECORDINGS IN 

PATIENTS WITH EPILEPSY 

Julie H. 1, Sandra P. 1, Jean G. 1, Marilyn J. 1 1Neuropsychology and 

Cognitive Neuroscience, McGill University, Montreal, Quebec, Canada 

It is known that emotionally arousing events are remembered better 

than neutral ones, but this has not been explored in olfaction. Increasing 

evidence indicates that the amygdala plays key roles in emotion and 

memory, and electrophysiological studies show that the human 

amygdala is implied in recognition memory for odors. In the present 

study we assessed memory for emotional and neutral odors in patients 

with temporal-lobe epilepsy undergoing intracranial recordings and 

examined the related olfactory evoked potentials (OEPs) in amygdala. 

Behavioral and electrophysiological results were obtained in 8 patients 

implanted in the amygdala (6 bilaterally, 1 left, 1 right). Patients´ 

behavioral data were compared to those of 10 healthy control subjects. 

Memory for pleasant, unpleasant or non emotional odors was tested 24 

hours after incidental encoding. Odor recognition was similar in 

patients and controls. OEPs were observed in the amygdala, composed 

mainly of a large positive peak occurring at a mean latency of 300ms. 

An effect of odorant´s emotional arousal was found in the right 

amygdala, with shorter latencies for emotional than for neutral 

odorants. This effect was specific to the amygdala, as similar OEPs 

were not found in the hippocampus. The results provide 

electrophysiological evidence for the postulated role of amygdala in 

memory for emotionally arousing material. The significance of the 

laterality of this effect will be explored with respect to the healthiness 

of left versus right amygdala in individual patients. Supported by Savoy 

Foundation and Canadian Institutes of Health Research.


OLFACTORY DYSFUNCTION IN DEGENERATIVE ATAXIAS. 

Connelly T. 1, Farmer J.M. 2, Lynch D.R. 3, Tourbier I.A. 4, Doty R.L. 4 

1Smell and Taste Center, Department of Otorhinolaryngology, 

University of Pennsylvania Medical Center, Phila, PA; 2Division of 

Medical Genetics, University of Pennsylvania Medical Center, 

Philadelphia, PA; 3Neurology, University of Pennsylvania Medical 

Center, Philadelphia, PA; 4Smell and Taste Center, Department of 

Otorhinolaryngology, University of Pennsylvania Medical Center, 


Several lines of evidence suggest that the cerebellum may play a role 

in higher-order olfactory processing. In this study, we administered the 

University of Pennsylvania Smell Identification Test (UPSIT), a 

standardised test of olfactory function, to patients with ataxias primarily 

due to cerebellar pathology (spinocerebellar ataxias and related 

disorders) and to patients with Friedreich ataxia, an ataxia associated 

mainly with loss of afferent cerebellar pathways. UPSIT scores were 

slightly lower in both patient groups than in the control subjects, but no 

differences were noted between the scores of the Friedreich and the 

other ataxia patients. Within the Friedreich ataxia group, the smell test 

scores did not correlate with the number of pathologic GAA repeats (a 

marker of genetic severity), disease duration, or categorical ambulatory 

ability. UPSIT scores did not correlate with disease duration, although 

they correlated marginally with ambulatory status in the patients with 

cerebellar pathology. This study suggests that olfactory dysfunction 

may be a subtle clinical component of degenerative ataxias, in 

concordance with the hypothesis that the cerebellum or its afferents 

plays some role in central olfactory processing. 

Supported by NIH Research Grants PO1 DC 00161, RO1 DC 04278, 

RO1 DC 02974, RO1 AG 17496 (RLD) and a Beeson Scholar Award 

(DRL) from AFAR 


DIAGNOSTIC OPTIONS AND LIMITS IN PATIENTS WITH 

OLFACTORY DYSFUNCTION AFTER HEAD INJURY 

Haxel B.R. 1, Mann W. 1, Mackay-Sim A. 2 1Otorhinolaryngology, 

University of Mainz, Mainz, Germany; 2Psychology, Griffith University, 

Brisbane, Queensland, Australia 

Objective: In this study patients with impaired olfaction after head 

trauma were investigated using smell tests and immunohistochemistry 

and cell-cultures of biopsies of the olfactory epithelium to trace specific 

changes. 

Methods: We investigated the sense of smell with Sniffin´ Sticks, 

chemosensory evoked potentials and biopsy of the olfactory epithelium 

using neurofilament and beta;-tubulin type III to detect immature 

neurons on frozen sections and cultures. The results were compared 

with age- and gender-matched normosmic controls. 

Results: In 5 patients complete anosmia was found in the Sniffin´ 

Sticks test, but only in 3 patients olfactory evoked potentials were 

missing completely. The biopsies showed intact olfactory epithelium 

with immature neurons in some cases, cell adhesion was found in 25% 

to 100% of the cultures and neurogenesis could be induced under the 

influence of growth factors. 

Conclusions: Head trauma can cause comprehensible olfactory 

impairment; there are different possible sites of a lesion. Olfactometry 

shows an intact neural transmission to the brain. Biopsies of the 

olfactory epithelium reveal the regeneration capacity of the receptor 

neurons. 

Acknowledgements: This study was supported by the Deutsche 

Forschungsgemeinschaft HA-3447/1-1, Germany and by the Garnet 

Passe and Rodney Williams Memorial Foundation, Australia. 

88 


OLFACTORY DEFICITS IN SINONASAL DISEASE 

Kern R.C. 1, Conley D.B. 1, Robinson A.M. 1 1Otolaryngology-HNS, 

Northwestern University, Chicago, IL 

Background: Chronic sinonasal disease is a common cause of smell 

loss but the pathophysiology is unclear. Human biopsy specimens 

indicate direct inflammatory changes in the epithelium, although it 

remains unclear how this mediates clinical olfactory deficits. It has been 

suggested that inflammatory cytokines may alter secretion and/or affect 

neuronal viability. Under normal conditions, olfactory sensory neurons 

undergo apoptotic cell death at a baseline rate matched by the 

regeneration of mature OSNs from precursors in the epithelium. The 

current study examines normal and diseased olfactory mucosa for 

evidence of a disturbance in this balance, which result in a net loss of 

OSNs. Study Design: Histologic analysis of human and animal 

olfactory tissue. Methods: Normal and inflamed human and animal 

olfactory mucosa was assessed for immunohistochemical evidence of 

apoptosis. Results: Increased activity of the apoptotic effector enzyme 

caspase-3 was demonstrated in diseased olfactory mucosa in 

comparison with normal controls in both human and animal tissue. 

Conclusion: These results support the hypothesis that olfactory deficits 

in sinusitis result from increased apoptotic OSN death apparently not 

matched by regeneration. Interference with the apoptotic pathway is 

currently the subject of intense pharmaco-therapeutic research. 

Potential treatment options will be discussed. Supported by the 

department of Otolaryngology-HNS. 


CHEMOSENSORY CHANGES FROM EXPOSURE TO 

FORMALDEHYDE IN ANATOMY LABS 

Dalton P. 1, Gould M. 1, Opiekun R. 1 1Monell Chemical Senses Center, 


More than 10% of the U.S. workforce (~14 million people) has daily 

occupational exposure to chemicals or particulates and as many as 40% 

of these individuals report symptoms of chronic nasal inflammation or 

rhinitis that are known precursors of olfactory loss. Moreover, evidence 

suggests that occupational chemical exposure increases the risk of ageassociated 

olfactory disorders. Despite this, the evaluation of olfactory 

function in susceptible occupational cohorts is rarely performed and 

consequently, little is known about the mechanisms underlying 

chemical-induced olfactory changes. This study evaluated the 

chemosensory impact of repetitive exposure to formaldehyde among 

veterinary students enrolled in anatomy labs, using a comprehensive 

assessment of threshold, secretory, and inflammatory parameters. 

Personal exposures for each participant were collected using passive 

dosimeters in order to evaluate observed changes in olfactory 

performance as a function of exposure concentration. Consistent with 

studies in formaldehyde-exposed animals, mucociliary clearance time 

increased with exposure duration for the students, but not unexposed 

controls, an outcome which may predispose individuals to both 

perceptual changes and nasal health effects following chemical 

exposures. 

Supported by NIH P50 P50 DC00214


QUALITATIVE OLFACTORY DYSFUNCTION: FREQUENCY 

AND PROGNOSTIC SIGNIFICANCE 

Hummel T. 1, Maroldt H. 1, Frasnelli J. 1, Landis B.N. 2, Hüttenbrink K. 3, 

Heilmann S. 4 1ORL, University of Dresden Medical School, Dresden, 

Germany; 2ORL, University Hospital of Geneva, Geneva, Switzerland; 

3ORL, University of Dresden, Germany, Dresden, Germany; 4ORL, 

University of Dresden, Dresden, Germany 

This study aimed to investigate frequency and prognostic 

significance of qualitative olfactory dysfunction (parosmia, 

phantosmia). A total of 868 patients were included; 160 of these 

patients (18%) complained of parosmic sensations, 59 (7%) mentioned 

odor phantoms. In patients without qualitative olfactory dysfunction, 

smell loss was most likely due to trauma (30%), infection of the upper 

respiratory tract (23%), sinunasal disease (17%) or it was idiopathic 

(22%). In patients with parosmia these figures were 7%, 70%, 8%, and 

12%; in patients with odor phantoms they were 20%, 54%, 15%, and 

17%. Thus, parosmias and phantosmias were most frequently 

encountered in olfactory loss following URTI. 

Among hyposmic patients those with parosmia exhibited a better 

discrimination of odorants but were less proficient in odor identification 

when visiting first. However, at second visit there was no significant 

difference between patients with (n=67) or without parosmia (n=223). 

In patients with parosmia decreased olfactory function was found in 

22%, improvement in 39%. Similar figures were seen in patients 

without parosmia (21%, and 40%). When visiting first patients with 

phantosmia were significantly worse in terms of odor identification 

compared to patients without phantosmia. At return visit in 38% of the 

phantosmic patients overall olfactory function was decreased; 

improvement was found in 41% of the patients. In conclusion, 

parosmias are found most frequently in olfactory dysfunction following 

URTI. Apparently, the presence of parosmia is not a predictor of the 

prognosis of olfactory dysfunction. In contrast, phantosmias appear to 

indcate a higher likelihood for a further decrease of olfactory fucntion. 

89 


HIGH INCIDENCE OF FUNCTIONAL ANOSMIA IN THE 

GENERAL POPULATION 

Landis B. 1, Konnerth C. 2, Hüttenbrink K. 3, Hummel T. 4 1University 

Hospital of Geneva, Geneva, Switzerland; 2ENT, University Hospital of 

Dresden, Dresden, Germany; 3Otorhinolaryngology, University of 

Dresden Medical School, Dresden, Germany; 4University of Dresden 

Medical School, Dresden, Germany 

Objective: To assess the incidence of anosmia and hyposmia in the 

general population. 

Study Design: Open prospective study ruled out on a population 

based sample representative for the German population. 

Methods: A total of 1240 subjects were included. Participants 

received an ENT examination and olfactory testing. Patients reporting 

sinu-nasal disorders were excluded. Olfactory testing was done by 

means of the Sniffin´ Sticks. 

Results: In 5% of the subjects nasal polyposis was diagnosed in the 

absence of sino-nasal complaints, confirming high incidence of nasal 

polyposis previously reported. In the remaining 1182 subjects (603 

men, 579 women) functional anosmia was detected at a frequency of 

4.7 %, whereas incidence increased with age (Fig. 1). Hyposmia was 

found in 16 % of the subjects. Most subjects with functional anosmia 

were unaware of their poor performances; accordingly, they could not 

indicate an origin of the anosmia. No significant sex-related difference 

in functional anosmia rate was detected. Similar to other authors we 

found age to be a main factor leading to functional anosmia. However, 

the present data also revealed functional anosmia to occur in up to 5 % 

of subjects under 65 years of age. 

Conclusion: The current findings suggest that severe olfactory 

alteration occurs at a much higher frequency than previously assumed, 

especially among younger people. Since olfactory deficits have been 

shown to occur in several general pathologies and especially in 

neurodegenerative diseases in their early phase, anosmia must be 

considered more than just a symptom of chronic sinu-nasal disease and 

deserves the general physicians attention. The present data also show 

the need of further research into treatments of olfactory disorders. 


ESTROGEN REPLACEMENT THERAPY: DOES IT AFFECT 

SMELL FUNCTION IN POST-MENOPAUSAL WOMEN? 

Neff J.K. 1, Knipe C. 1, Doty R.L. 1 1Smell and Taste Center, Department 

of Otorhinolaryngology, University of Pennsylvania Medical Center, 


Decreased smell function is among the first signs of Alzheimer´s 

disease. Although controversial, there is evidence that estrogens 

mitigate verbal memory and several other cognitive deficits that are 

associated with Alzheimer´s disease. Thus, the question arises as to 

whether estrogens mitigate olfactory deficits observed in the older 

female population. This retrospective study focuses on estrogen 

replacement therapy (ERT) and its possible role in decreasing olfactory 

loss in post-menopausal women. Currently, 257 women of an 

anticipated 600 women have participated in the study. Preliminary 

analyses have focused on olfactory scores of women during the first ten 

years after menopause. Within this subset of our sample population, 

there is a tendency for women who are currently on ERT to have higher 

olfactory scores in comparison to women who are not currently taking 

ERT. Within this limited age range, no meaningful association between 

prior estrogen use and olfactory test scores has yet emerged. Additional 

preliminary analyses suggest there may be a correlation between ERT 

use and decreased verbal cognitive deficits. Future analyses will 

explore the effect of ERT on age-related olfactory and memory deficits 

beyond the first ten years after menopause. 

This abstract was supported by the following grant from the National 

Institutes of Health, Bethesda, MD: RO1 AG 17496-04


MODELING OF AIRFLOW AND ODORANT DELIVERY 

PATTERN IN A PRE- & POST-OPERATIVE NASAL CAVITY: 

A QUANTITATIVE EVALUATION OF SURGICAL 

INTERVENTION 

Zhao K. 1, Scherer P.W. 1, Cowart B.J. 2, Pribitkin E.D. 3, Rosen D. 3, 

Dalton P. 2 1Bioengineering, University of Pennsylvania, Philadelphia, 

PA; 2Monell Chemical Senses Center, Philadelphia, PA; 3Department 

of Otolaryngology-Head and Neck Surgery, Thomas Jefferson 

University, Philadelphia, PA 

Mechanical obstruction of odorant flow to olfactory receptor sites 

due to inflammation or polyps is a primary cause of olfactory loss in 

nasal-sinus disease patients. In these cases, surgical intervention (e.g. 

removal of polyps) can effectively facilitate recovery of olfactory 

ability. Using computational fluid dynamics (CFD) techniques, we are 

able to quickly convert nasal C-T scans from an individual patient at a 

given time point (e.g., pre-post surgery) into anatomically accurate 3-D 

numerical nasal models that can be used to predict nasal airflow and 

odorant delivery patterns. Our goal is to correlate the patient´s olfactory 

recovery with improvement of odorant delivery rate to receptor sites at 

various times during the treatment. 

In this preliminary study, we followed the treatment of a patient 

who had lost most of her orthonasal and all of her retronasal olfactory 

ability, but regained it after surgical treatment of polyps. CFD modeling 

of this patient´s nose before and after surgery showed significant 

improvement in ortho & retronasal odorant delivery and suggested that 

remodeling the airway was a significant factor leading to the recovery 

of olfactory function. In the future, such modeling techniques may 

serve as a quantitative evaluation of surgical procedures and an 

important pre-surgical guide to the optimization of airflow and odorant 

delivery in the human nose. 

Supported by NIH P50 DC00214 


DIAGNOSIS AND SURGICAL TREATMENT OF PAROSMIA 

Pitovski D.Z. 1, Goins M. 1 1WFU Smell and Taste Center, Dept. of 

Otolaryngology, Wake Forest University, Winston-Salem, NC 

The purpose of this study was to determine whether transnasal 

endoscopic excision of the olfactory mucosa is an effective and safe 

treatment in patients diagnosed with unilateral parosmia and to learn 

more of its pathogenic features by examining the histological 

characteristics of the excised mucosa. The two patients (patient A and 

B) who were subjected to the surgery both had complete and permanent 

resolution of their parosmia. Ninety-days after surgery, olfactory 

assessment revealed no change (in comparison to preoperative status) in 

olfactory ability on the operated nostril in patient A, while improved in 

olfactory ability in patient B. No changes in olfactory capacity were 

noted in the contralateral (unoperated) nostrils. Patient A and patient B 

had unremitting parosmia for 3 years and 20 years, respectively. The 

excised olfactory mucosa showed abnormal histological features that 

would suggest some pathological condition in the peripheral olfactory 

system. To the best of our knowledge, this is the first report that has 

demonstrated effective treatment of patients who suffer from parosmia 

through surgical technique. Furthermore, the abnormal histological 

features of the excised olfactory mucosa and its excision in the 

treatment of the parosmia suggest that there is a peripheral 

pathophysiological mechanism. 

90 


ODORANT-INDUCED EXACERBATION OF BURNING 

MOUTH SYNDROME 

Hirsch A.R. 1 1The Smell & Taste Treatment and Research Foundation, 

Chicago, IL 

BMS presents with symptoms of burning, pain, phantageusia. We 

present 3 patients, exposed to odorants precipitated severe burning 

exacerbation. (1) 83 year-old woman, 2 years burning, salty 

phantageusia, onset immediately following application of nitroglycerin. 

Burning worsened with ingesting hot or spicy food, stress, and 

lidocaine application. Acute severe exacerbation of BMS precipitated 

with exposure to Carbinol in the Olfactory Test of Amoore. (2) 57 yearold 

male, 1year sudden onset of idiopathic metallic phantageusia and 

BMS. Burning worsened after consuming coffee, chocolate and cola, 

reduced with chewing gum or eating salty food. Upon exposure to 

aromas of shampoo or soap, the BMS and associated phantageusia were 

exacerbated. (3) 59 year-old woman, 1 year of gradual onset 

hypogeusia, metallic and spicy phantageusia, salty and spicy dysgeusia, 

and BMS. Burning worsened with eating spicy food; reduced with 

sucking sweet candy and drinking diet Coke. When presented with 

odors of gas or garage, severe burning mouth symptoms recurred. 

Possible mechanisms of odorants: stimulate hunger, thus precipitate 

salivary flow, change chemical content of the mouth, which 

hypersensitive pain fibers interpret as pain; induce eating memories, 

stimulate gastroesophageal reflux, change in mouth PH causing pain; 

induce cephalopancreatic reflex, causing decreased blood sugar 

allowing dysfunctional pain nerve fibers to fire; trigeminal component 

of odors may act on tongue to precipitate prolonged, intense burning; 

stressors which worsens BMS. BMS may represent a form of 

synesthesia, seen in neurological conditions such as odor-sensitive 

migraine, or post-amputation phantom limb–in which otherwise 

innocuous stimuli precipitate pain. 

345 Poster [ ] Olfactory Regeneration 

APRIN IN RAT OLFACTORY EPITHELIUM 

Weiler E. 1, Farbman A.I. 2 1Neurophysiology, Ruhr-Universität, 

Bochum, Germany; 2Neurobiology and Physiology, Northwestern 

University, Evanston, IL 

Aprin (androgen-induced prostate proliferative shutoff associated 

protein AS3) inhibits cell proliferation in the prostate and protects 

against carcinogenesis. Although proliferation in the olfactory 

epithelium (OE) continues during adulthood OE doesn't develop 

tumors. We asked whether aprin is expressed in the rat OE. We report 

here the sequence of rat aprin (Accession # AY388627) and the 

expression of aprin mRNA in the olfactory epithelium of postnatal rats 

using RT-PCR and (competitive) duplex PCR. Semiquantitative 

estimates reveal that aprin mRNA expression level in the OE is lower 

(~8x) compared to that in testis. Although proliferation dramatically 

decreases in rat OE postnatally, the expression level of aprin does not 

change much. Besides the OE, aprin mRNA is also expressed in other 

neuronal (olfactory bulb, visual cortex, cerebellum, eye, adrenal gland) 

and non-neuronal tissues (testis, kidney, heart, lung, and very weak 

expression in muscle, intestine, liver) with highest expression in testis. 

No differences between males and females were observed in aprin 

expression in OE. Aprin function is discussed in relation to cell 

turnover and neuronal survival. 

Supported by NIH Grants # DC04637, DFG Grant SFB509 TPC4, 

FORUM F108/00 M122/13).


REDUCED TARGET ABLATION-INDUCED MACROPHAGE 

RECRUITMENT AND ACTIVATION IN MIP-1 KNOCK-OUT 

(KO) MICE IS RESTORED BY MIP-1 INJECTION 

Getchell M.L. 1, Kwong K. 2, Vaishnav R.A. 1, Getchell T.V. 3 1Anatomy 

& Neurobiology, Univ. of KY, Lexington, KY; 2Physiology, Univ. of KY, 

Lexington, KY; 3Sanders-Brown Ctr. on Aging, Univ. of KY, Lexington, 

KY 

The chemokine macrophage inflammatory protein (MIP)-1α (CCL3) 

recruits macrophages (mφs) to sites of epithelial remodeling. We 

showed that MIP-1α mRNA and protein levels in the olfactory 

epithelium (OE) increase significantly at 3 d post-olfactory bulbectomy 

(OBX). Our specific aim was to investigate the effect of lack of MIP-1α 

on mφ infiltration after OBX in MIP-1α KO mice compared to wildtype 

(wt) mice and to test if function was restored in KO mice by MIP- 

1α injection. OBX was performed on wt and MIP-1α KO mice; all 

received 6 injections at 12-h intervals of either 10 µg/ml MIP-1α 

protein in carrier (0.5% BSA in sterile saline) or carrier alone for 3 d. 

Mφ infiltration was evaluated with antibodies to CD68 for resident mφs 

and F4/80 for activated mφs. Compared to wt mice, CD68 + mφ 

numbers in the OE were 59% less than in carrier-injected KO mice and 

only 28% less in MIP-1α-injected mice (p


DIFFERENTIAL RESPONSES TO BULBECTOMY AND 

MINOCYCLINE-HCL IN BAX DEFICIENT AND WILD TYPE 

MICE 

Robinson A.M. 1, Conley D.B. 1, Kern R.C. 1 1Otolaryngology-HNS, 

Northwestern University, Chicago, IL 

In contrast to wild type mice, bax deficient mice demonstrate an 

early but short-lived wave of olfactory sensory neuron (OSN) apoptosis 

in response to unilateral bulbectomy that gives way to apoptosis 

resistance, at least up to 9 days post-surgery. In order to elucidate early 

events in OSN apoptosis following bulbectomy we compared changes 

in gene expression and epithelial thickness in wild type and bax 

deficient mice and in mice treated with minocycline-HCl. The antibiotic 

minocycline-HCl has been shown to have an anti-apoptotic effect in 

other systems and is in clinical trials for therapeutic use in Parkinson´s 

disease. In other systems, the mechanism of minocycline-HCl apoptosis 

inhibition is believed to be at the level of inhibition of cytochrome c 

release from the mitochondria. This inhibition would suppress 

activation of caspase-9 and the downstream caspases, including 

caspase-3. Given that bax promotes cytochrome c release, it was 

anticipated that apoptosis in the bax knockout mouse may be further 

suppressed by minocycline-HCl. By epithelial thickness measurement 

there appears to be an initial inhibition of apoptosis in wild type mice 

receiving minocycline-HCl. In contrast, the initial apoptosis following 

bulbectomy typically observed in bax deficient mice was not 

ameliorated. This lack of additional apoptosis inhibition in 

minocycline-HCl treated bax deficient mice may be explained by our 

results from cDNA expression arrays that focused on apoptotic gene 

expression. Bax deficient mice show a dramatic increase in caspase-3 

mRNA by 8 hours post-bulbectomy that was absent in wild-type mice. 

Supported by the department of Otolaryngology-HNS. 


OEC DYNAMICS IN THE OLFACTORY SYSTEM OF 

METHIMAZOLE-LESIONED & CONTROL MICE 

Iwema C.L. 1, Dodds T. 1, Chin J. 1, Greer C.A. 1 1Neurosurgery, Yale 

University School of Medicine, New Haven, CT 

Olfactory sensory neuron (OSN) axons are held in juxtaposition by 

specialized glia, the olfactory ensheathing cells (OECs), as they extend 

towards the olfactory bulb (OB). It has been suggested that OECs 

provide a favorable substrate for axon outgrowth and potentially assist 

with targeting and/or glomerular recognition. Damage to the olfactory 

system (OS) results in incorrect target recognition by the OSNs; the 

effect of injury on the OECs is unknown. One hypothesis is that OECs 

fail to correctly ensheath and/or sort OSN axons following lesions. The 

effect of growth/guidance molecules associated with OECs on the 

olfactory projection after injury remains ambiguous. Despite the 

apparent inability of newly developed OSN axons to accurately target 

following lesions, they nonetheless do innervate glomeruli in the OB, 

albeit in an indiscriminate manner. What happens to the OECs during 

this process? We used established immunohistochemical protocols with 

antibodies to tyrosine hydroxylase (TH), GAP43, NCAM and S100 to 

evaluate changes in the mouse OS during degeneration (5 days, 10d), 

reinnervation (30d, 60d), and recovery (90d) following exposure to the 

olfactoxin, methimazole. Our data demonstrate that TH expression is 

initially decreased in the OB but recovers by 90d post-lesion, whereas 

GAP43 expression is markedly upregulated at 10d post-lesion before 

returning to baseline. In addition, we addressed OEC turnover using 

both BrdU and a marker for apoptosis (NeuroTACS II) and report 

evidence of both OEC genesis and death in control tissue. Thus, OECs 

appear to be dynamic agents in the normal adult OS. NIH DC00210, 

DC06291. 

92 


EARLY OLFACTORY ENRICHMENT DECREASES TUNEL- 

POSITIVE CELLS IN OLFACTORY BULBS OF NEONATAL 

RATS. 

Woo C.C. 1, Hingco E.E. 1, Taylor G.E. 1, Johnson B.A. 1, Leon M. 1 

1Neurobiology and Behavior, University of California, Irvine, Irvine, 

CA 

A proportion of rat olfactory bulb interneurons normally undergo 

postnatal cell death, as is evident by both a decrease in the total 

numbers of interneurons after the second postnatal week, and the 

presence of TUNEL-positive cells in most layers of the main olfactory 

bulb at that time. In the current study, we determined whether increased 

olfactory experience could save olfactory bulb cells from an early 

death. To that end, we examined the effects of early olfactory 

enrichment on cell death in the main olfactory bulb. Rats were exposed 

continuously to a battery of natural and artificial odorants that were 

changed daily from postnatal days (PNDs) 1-15. On PND 16, TUNELpositive 

cells were quantified in both the granule cell layer and the 

glomerular layer of the main olfactory bulb. Early olfactory enrichment 

resulted in a statistically significant decrease in the number of TUNELpositive 

cells present in both of these layers. In addition, we examined 

the effects of odor enrichment on the neural response to odorants using 

[14C]2-deoxyglucose. Odor enrichment during the first three postnatal 

weeks resulted in a statistically significant increase in activity in the 

glomerular layer in response to odorants. These data suggest that 

olfactory enrichment during the early postnatal period can save 

olfactory bulb cells from dying, and can also enhance the glomerular 

response to odorants. This research was supported by NIDCD grant 

#DC03840 to M.L. 


CASPASE 8 ACTIVATES ORN APOPTOSIS FOLLOWING 

DEAFFERENTATION AND EXCITOTOXIC LESION OF 

MOUSE OLFACTORY BULB 

Fung F.W. 1, Carson C. 1, Saleh M. 2, Nicholson D. 2, Roskams J. 1 

1Zoology, University of British Columbia, Vancouver, British Columbia, 

Canada; 2Merck Frosst, Montreal, Quebec, Canada 

Our lab has been testing how signals initiated at the olfactory bulb 

mitral cell synapse may regulate the apoptosis of olfactory receptor 

neurons (ORNs). We have previously shown that, following olfactory 

bulbectomy, ORNs undergo apoptosis driven by caspase-9 and 3mediated 

retrograde axonal signaling. Because a bulbectomy is also a 

distal axotomy, we modified our lesion model to remove only the ORN 

target neurons (mitral and tufted cells) in the olfactory bulb using 

NMDA-mediated excitotoxicity. We find that NMDA infused directly 

into the olfactory bulb effectively kills off the majority of bulbar mitral 

and tufted cells within 48 hrs of being administered. Surprisingly, most 

OMP-positive mature ORNs do not immediately undergo target 

deprivation-induced apoptosis following NMDA infusion, and despite 

the loss of functional glomeruli, a significant population of their axons 

persist for up to 8 days in the nerve fiber layer. A delayed form of 

apoptosis does appear to eventually occur (by 4 days after loss of 

postsynaptic target) in a sub-population of vulnerable ORNs in NMDAlesioned 

mice. We have identified caspase 8 as the apical caspase first 

activated at the glomerular synapse. We demonstrate (by coimmunoprecipitation) 

that Dynactin, a DED (Death Effector Domain) - 

containing protein, is a retrograde motor complex protein that can 

regulate the transport and/or activation of caspase 8 in ORNs following 

target lesion. Finally, by using taxol to inhibit axonal microtubule 

motors following bulbectomy, we can delay caspase-mediated 

retrograde apoptosis in ORNs. 

Supported by NIH (NIDCD) 5RO1 DC04579-03 to JR

352 Slide [ ] Odorant Receptors 

COMPARATIVE GENOMICS OF OLFACTORY RECEPTOR 

GENE CLUSTERS 

Young J.M. 1, Newman T. 1, Schlador M. 1, Linardopoulou E. 1, Walker 

M. 1, Hsu J. 1, Williams E. 1, Trask B.J. 1 1Division of Human Biology, 

Fred Hutchinson Cancer Research Center, Seattle, WA 

Comparison of the nearly complete genomes of rat, mouse, and 

human reveals extensive lineage-specific change in the olfactory 

receptor (OR) gene repertoires of these species. The primary 

contributor to repertoire change has been recent duplications that create 

new genes. Genes have also been lost through deletion and mutation. 

Only ~400 human genes appear to be functional, compared to ~1210 for 

mouse and ~1390 for rat. Our cDNA screen of olfactory 

neuroepithelium confirmed expression there for over one third of the 

intact mouse OR genes and also revealed extensive alternative splicing 

within the 5ÚTRs of OR transcripts. We observe up to a 300-fold 

difference in mRNA levels among mouse OR genes, which appears to 

be due to differences in both the number of expressing cells and the 

number of transcripts per cell. The family expanded primarily through 

local duplications in all three species, but inter-chromosomal 

duplications also occurred in both the human and rat lineages. 

Intriguingly, these inter-chromosomal duplications involved large 

genomic segments (up to 800 kb) containing primarily OR 

pseudogenes. The complex structures and evolutionary relationships 

among these regions suggest that they are subject to ongoing gene 

conversion-like ectopic exchange subsequent to the original 

duplication. The propensity of these segmental duplications to undergo 

recombination can also lead to gross allelic variation among normal 

individuals and /or the formation of chromosome abnormalities 

associated with disease. Funded by NIH DC004209 and GM057070. 

353 Poster [ ] Odorant Receptors 

HANDS OFF MY ENDANGERED SPECIES: LOW ALLELIC 

VARIATION OF SEA TURTLE OR GENES SUPPORTS 

IMPORTANCE OF OLFACTORY SENSE. 

Vieyra M. 1, Vogt R.G. 1 1Biological Sciences, University of South 

Carolina, Columbia, SC 

How to determine the importance of a given sense to the life history 

of an endangered species when government regulations prohibit direct 

physiological analysis? Estimate the evolutionary selective pressure 

acting on the sense. Clone an "important" gene and examine its allelic 

variation within a population; low variation suggesting selection is 

strong and that the sense is important to the life history of the animal, 

high variation suggesting selection is low and that the sense is less 

important. Cloning and characterizing genes of endangered species is 

feasible because archives of DNA samples OR genes were cloned from 

3 sea turtles (loggerhead, green, leatherback), 4 freshwater or terrestrial 

turtles (musk, painted, box, gopher tortoise) and American alligator. 

These genes are more similar to the mammalian than to the fish OR 

gene subfamily. Sea turtles have a reduced number of OR genes and a 

greater number of OR pseudogenes (internal stop codons) than 

freshwater or terrestrial turtles. Population analysis of 5 sea turtle genes 

indicates a strong dominance of a single allele for conserved genes, and 

a surprisingly low level of allelic variation among pseudogenes. These 

findings suggest olfaction is important and that pseudoization may be a 

relatively recent event if not an ongoing process. Turtles have similar 

sized OR and VNO systems; VNO neurons are thought to convey 

aquatic signals. The presence of strongly selected OR genes suggests 

that airborne odors may be important signals for sea turtles. Funding: 

NOAA 

93 


EXPRESSION OF CANDIDATE GUSTATORY RECEPTOR 

GENES IN ANOPHELES GAMBIAE 

Kent L.B. 1, Robertson H.M. 1 1Entomology, University of Illinois at 

Urbana-Champaign, Urbana, IL 

The ability to detect and discriminate between chemical cues in the 

environment is key to successful host finding in mosquitoes. The recent 

availability of the genome sequence of Anopheles gambiae, the 

principle vector of human malaria in Africa, has allowed for the 

identification and annotation of the genes believed to encode odorant 

(AgOr) and gustatory (AgGr) receptor genes in the mosquito. These 

genes are members of the G-coupled protein receptor (GCPR) 

superfamily of chemoreceptors, characterized in part by their seventransmembrane 

domains. Phylogenetic analysis reveals that only a few 

orthologous pairs of the genes have been conserved between 

Drosophila and Anopheles. Otherwise, most Ors and Grs form speciesspecific 

gene subfamilies. We have begun studies of the expression 

patterns of the putative AgGr genes, based upon an RT-PCR assay. In 

this way, we can examine the conservation of expression of Grs in A. 

gambiae over the roughly 250 million years since it diverged from the 

lineage containing Drosophila melanogaster. Patterns of similarity 

across the two species are apparent. Three of the genes (AgGr22, 

AgGr23, AgGr24) with high sequence similarity to two genes in 

Drosophila melanogaster (DmGr21a and DmGr63a) are expressed in 

antennae and maxillary palps, which matches the expression patterns 

seen in Drosophila. Interestingly, DmGr21a has recently been 

identified by Dr. Marien de Bruyne, at the Freie Universität Berlin, as a 

candidate carbon dioxide receptor in Drosophila. We are in the process 

of determining whether the closely related anopheline genes share the 

same function. This research is funded by NIH RO1AI056081. 


EXPRESSION OF AN ANOPHELES GAMBIAE CANDIDATE 

ODORANT RECEPTOR IN A SUBSET OF DISTINCT 

SENSILLA ON THE PROBOSCIS INDICATES A POTENTIAL 

OLFACTORY FUNCTION 

Pitts J. 1, Rützler M. 1, Zwiebel L. 1 1Biological Sciences and Center for 

Molecular Neuroscience, Vanderbilt University, Nashville, TN 

The biting behavior of Anopheles gambiae (An. gambiae) is largely 

influenced by olfactory cues emanating from host animals. The strong 

preference of the An. gambiae s.s. species for human hosts contributes 

significantly to the transmission of human malaria in sub-Sahara Africa. 

The family of odorant receptor genes in An. gambiae encodes G 

protein-coupled receptors for which some ligands have been identified. 

One of these genes, GPRor7, is highly conserved with respect to single 

genes from many insect orders. Immunocytochemistry demonstrates 

that its protein product is localized to most sensilla of olfactory organs 

of An. gambiae. By RT-PCR analysis, GPRor7 is also expressed in the 

proboscis of An. gambiae, a known gustatory organ in other 

mosquitoes. Immunocytochemisry indicates that GPRor7 is found 

within each of a small subset of sensilla on the labellar lobes, a pair of 

bulbous organs at tip of the proboscis. Scanning electron micrographic 

analysis reveals that the GPRor7 expressing sensilla are short, grooved 

hairs residing in a socket on the cuticle surface and that there are about 

25 of these hairs per labellar lobe. Their morphology is reminiscent of 

other grooved olfactory sensilla, and the presence of an odorant 

receptor within them indicates either a potential olfactory function for 

them, or a potential gustatory function for GPRor7. This work was 

supported by grants from the National Institutes of Health: the NIDCD 

and the NIAID.


OLFACTORY CODING IN PERIPHERAL ORGANS OF 

ANOPHELES GAMBIAE 

Kwon H. 1, Zwiebel L.J. 1 1Department of Biologial Sciences and Center 

for Molucualr Neuroscience, Vanderbilt University, Nashville, TN 

A principal goal in neuroscience is to understand how sensory 

information is processed and integrated to control a suitable behavioral 

output in a nervous system of an animal. Of these, olfactory cues are 

primarily used in an insect to find a host, mate, and oviposition site. 

Therefore, it is important to understand how olfactory coding occurs a 

peripheral olfactory organ as well as in central nervous system. In 

insects, olfactory transduction is initiated by G protein-coupled 

receptors in the cell membrane, which have been characterized in 

different insect species so far. In this study, using an important malaria 

vector mosquito, A. gambiae, from which 79 different G proteincoupled 

receptor genes have been found, we focus on functional 

analysis of olfactory information processing in antenna as well as 

proboscis where an odorant receptor gene (AgOR7) is also expressed. 

With analysis of gene expression in these appendages, here we aim to 

characterize central processing and olfactory coding in a primary 

olfactory and gustatory organ, antenna and proboscis, using 

electrophysiological methods and backfilling techniques. Recording 

from epithelia of antenna and proboscis was employed with several key 

mosquito odorant components. Here we report that proboscis shows 

olfactory responses to an odorant chemical. This result supports the idea 

that proboscis contributes olfactory perception in accordance with gene 

expression of the odorant receptor in proboscis. More detailed evidence 

of neural anatomy and single sensillum recording will be presented. 

(Supported by NIH grants A1056402 & DC04692) 


MOLECULAR ANALYSIS OF DROSOPHILA ODORANT 

RECEPTORS 

Benton R. 1, Vosshall L.B. 1 1Rockefeller University, New York, NY 

The Drosophila olfactory system is a powerful model to determine 

how neuronal circuits represent the external world in the brain. The 

peripheral circuitry has a striking stereotypical spatial organization. 

Olfactory sensory neurons (OSNs) express only one of ~60 odorant 

receptors (ORs) along with Or83b, a broadly expressed member of the 

OR gene family. The axons of OSNs expressing the same OR converge 

on specific glomeruli in the antennal lobe. Each class of OSN also 

displays distinct spiking properties in response to odor stimulation, 

suggesting that both temporal and spatial patterns of neuronal activity 

contribute to the representation of odor identity. 

ORs are polytopic membrane proteins that lie at the interface 

between the odorous environment and neuronal activity patterns. Little 

is known about their ligand specificity, what second messenger cascade 

couples receptor activation to neuronal spiking, or the mechanisms by 

which their activity and localization are regulated. Genetic analysis of 

candidate downstream signaling components has failed to reveal the 

involvement of a single canonical pathway, suggesting that multiple 

and/or novel cascades are involved. ORs are not expressed on the 

surface of heterologous cells, indicating that OSNs possess unique 

trafficking pathways integral to the localization and function of ORs. 

To dissect OR function and regulation, we have initiated a 

combination of molecular and transgenic approaches. We are using the 

yeast two-hybrid system to identify cytoplasmic factors that associate 

with their intracellular loops, and have generated a panel of epitopetagged 

ORs for biochemical analysis in vivo. 

Funding: EMBO, NIH and NSF 

94 


THE SPERM "NOSE": KEY ROLE OF PARTICULATE 

ADENYLATE CYCLASE 

Schwane K. 1, Spehr M. 1, Riffell J. 2, Barbour J. 1, Zimmer R. 2, Neuhaus 

E.M. 1, Hatt H. 1 1Cell Physiology, Ruhr-University Bochum, Bochum, 

Germany; 2Biology, University of California, Los Angeles, Los Angeles, 

CA 

Besides their 'conventional' role in olfaction, odorant receptors have 

long been suggested to function in mammalian sperm physiology and 

fertilization. Recently, Spehr et al. (2003) identified and characterized a 

human testicular odorant receptor, hOR17-4, that is activated by certain 

floral odorants (e.g. bourgeonal, scent of lilies of the valley) In 

additional behavioral bioassays, bourgeonal was found to act as a strong 

chemoattractant to navigating human sperm. Nevertheless, the 

molecular mechanisms that link hOR17-4 activation to sperm responses 

remain obscure. 

In imaging experiments as well as behavioral assays, we show here 

that a membrane-bound AC (mAC) couples OR activation to changes in 

sperm swimming behaviour, such as chemotaxis, chemokinesis, and 

hyperactive flagellar beating. 

Introducing a new approach of protein identification in mature sperm 

by mass spectrometry (mudpit) we provide evidence for expression and 

participation of specific receptors, G-proteins, and mACs in the 

underlying signaling cascade. Spatial distribution patterns of the 

identified signaling components largely correspond to the 

spatiotemporal character of odorant-induced Ca2+ changes viewed via 

single cell high-resolution imaging techniques. 

Taken together our data show that mAC activation is linked to sperm 

chemotaxis and hyperactivity and provide a basis for further 

investigations in the field of fertility and sterility. 

This work was generously sponsored by the Heinrich and Alma 

Vogelsang Foundation (to K.S.). 


CHEMICAL COMMUNICATION AND THE LANGUAGE 

SPOKEN BY SPERM AND EGGS 

Zimmer R. 1, Riffell J. 1, Krug P. 2 1Ecology and Evolution, University of 

California, Los Angeles, Los Angeles, CA; 2Biological Sciences, 

California State University, Los Angeles, Los Angeles, CA 

Chemical communication between sperm and egg is a critical factor 

mediating sexual reproduction. Sperm attractants may be significant 

evolutionarily for maintaining species barriers, and important 

ecologically for increasing gamete encounters. Still unresolved, 

however, are the functional consequences of these dissolved signal 

molecules. Here, we provide the first experimental evidence that sperm 

chemoattraction directly affects the magnitude of fertilization success. 

The recent discovery of L-tryptophan as a potent attractant to red 

abalone (Haliotis rufescens) sperm offered the opportunity to quantify 

how navigation affects gamete interactions. Sperm behavioral responses 

to manipulations of the natural tryptophan gradient around individual 

eggs revealed that both chemotaxis and chemokinesis significantly 

promote contacts. Our results showed further that attractant release via 

diffusion effectively doubles the target size of red abalone eggs, which 

in turn significantly increases fertilization success. Although long 

theorized as potential barriers to hybridization, species-specific sperm 

attractants in red and green (H. fulgens) abalone are only minor 

contributors to maintaining reproductive isolation. Because abalone 

typically live in dense, multi-species aggregations, chemically mediated 

navigation would prevent sperm from pointlessly tracking 

heterospecific eggs. Thus, even though reproductive isolation 

fundamentally resides at the level of membrane recognition proteins, 

species-specific sperm attractants may have evolved to locate the right 

target within mixed gamete suspensions of closely related species.


MOUSE TESTICULAR OLFACTORY RECEPTORS: 

EXPRESSION PATTERN, ODORANT RESPONSIVENESS, AND 

REGULATION OF SPERM MOTILITY. 

Fukuda N. 1, Yomogida K. 2, Okabe M. 3, Kataoka H. 1, Touhara K. 1 

1Department of Integrated Biosciences, University of Tokyo, Kashiwa, 

Chiba, Japan; 2Research Institute for Microbial Diseases, Osaka 

University, Suita, Osaka, Japan; 3Genome Information Research 

Center, Osaka University, Suita, Osaka, Japan 

Although a subset of olfactory receptor (OR) gene family is 

expressed in mammalian testis, developmental expression pattern and 

physiological function of testicular ORs have not been fully 

characterized. To clarify testicular OR function in mice, we first 

analyzed expression pattern of mouse OR genes in testis and found that 

ORs were expressed stage-specifically in round spermatids during 

spermatogenesis. We next conducted functional analysis of MOR23, a 

mouse testicular OR, that had been shown to recognize a floral odorant, 

lyral, in the olfactory system. Lyral elicited Ca2+ -increases in a fraction 

of spermatids and mature sperm in a dose-dependent manner. 

Comparison of lyral-responsiveness of germ cells derived from 

transgenic mice expressing MOR23 with that of wild type mice 

provided evidence that MOR23 mediated lyral-induced Ca2+ -increases 

in spermatids and spermatozoa. Finally, lyral induced sperm 

accumulation in chemotaxis assay, suggesting that MOR23 functioned 

as a chemosensor in mature sperm, and that the internal Ca2+ -increase 

via MOR23 affected the sperm motility. The MOR23-expressing 

transgenic mouse line generated in this study will be a powerful tool to 

identify endogenous ligand(s) that may be structurally related to lyral, 

with implications for physiological roles of mouse testicular OR(s). 


DISCOVERY OF ACETALS, ALCOHOLS, AND ESTERS AS 

ISOVALERIC ACID ODOR BLOCKERS 

Qi M. 1, Rogers D.H. 1, Warren C.B. 2, Darmohusodo V. 1 1Senomyx, Inc., 

La Jolla, CA; 2Chemosensory Perception Lab, UC San Diego, La Jolla, 

CA 

Isovaleric acid (IVA) is probably a potent agonist for one or more of 

the approximately 350 human olfactory receptors (Zozulya 2001). To 

find an odor blocker, we hypothesized a simple binding pocket based 

on known GPCR receptors and then designed antagonist candidates that 

would fit into this binding pocket. Each candidate was tested for its 

ability to reduce the perceived odor intensity of a 56 ppm solution of 

IVA in water (Target). The evaluation of blocking utilized a cross 

adaptation protocol in which the subject a) sniffed the target solution 

with both nostrils and scored its odor intensity on a Labeled Magnitude 

Scale (LMS); b) waited one minute, c) sniffed a 1% v/v solution of the 

candidate in diethyl phthalate twice with each nostril, and d) sniffed the 

target again with both nostrils. The reduction in IVA intensity between 

the first and third sniffing was used to calculate a % malodor reduction 

(MOR) for each candidate. The compounds that worked best have a 

hydrocarbon tail similar to that of IVA and a polar head. Of the 

homologous series tested, the acetals worked best with 2-isobutyl- 

[1,3]dioxane giving a MOR score of 97%. For the alcohols, 2methylcyclopropane 

methanol provided the best blocking with a MOR 

of 85%. For the ester series, the ethyl and methyl esters of IVA gave 

MOR scores of 94 and 92% respectively. The magnitude of blocking 

was much higher than the 25 to 30% odor reduction generally reported 

in the cross adaptation literature. These results suggest that we have 

identified antagonists for the primary IVA receptor. 

95 


HELA CELLS DESIGNED FOR FUNCTIONAL GENOMICS OF 

ODORANT RECEPTORS AND PHEROMONE RECEPTORS 

Shirokova E. 1, Schmiedeberg K. 1, Bedner P. 2, Niessen H. 2, Willecke 

K. 2, Harteneck C. 3, Raguse J. 4, Krautwurst D. 1 1Molecular Genetics, 

German Institute of Human Nutrition Potsdam-Rehbrücke, Nuthetal, 

Germany; 2Institute of Genetics, Bonn University, Bonn, Germany; 

3Institute of Pharmacology, Free University Berlin, Charité Campus 

Benjamin Franklin, Berlin, Germany; 4Clinic and Policlinic for Oral 

and Maxillofacial Surgery and Plastic Surgery, Charité, Berlin, 

Germany 

Odorant receptors (OR) of the main olfactory epithelium, and 

pheromone receptors (VR) of the vomeronasal organ, are the largest 

group of orphan G-protein-coupling receptors (GPCR), with a small 

number of ligands identified out of thousands of odorants and hundreds 

of pheromones. De-orphanization of OR was hampered by their 

combinatorial odorant coding, suboptimal plasma membrane 

expression, and lack of olfactory-specific signal transduction in 

recombinant cell systems. Heterologous functional expression of VR 

has not been reported, so far. We have achieved stable reconstitution of 

OR-specific signaling in HeLa cells, via G-protein αolf and adenylyl 

cyclase type-III to the olfactory cyclic nucleotide-gated CNGA2 

channel. In these cells, receptors of the V1R-type inhibit, via G protein 

αi, the cAMP pathway. In another cell line, we established stable 

expression of a TRP channel that can be activated by pheromones via 

V1R and phospholipase C-β2. CNGA2 or TRP channels translate 

changes in intracellular cyclic nucleotides into changes in Ca 2+ -influx 

that can be monitored by means of fluorescence imaging multiwellplate 

reader techniques. This allows us to functionally characterize the 

de-orphanized OR and V1R by EC 50 -ranking odorant profiles.


MECHANISM FOR OLFACTORY RECEPTOR-ODORANT 

INTERACTIONS 

Crasto C.J. 1, Lai P.C. 2, Singer M. 3, Shepherd G.M. 1 1Neurobiology, 

Yale University, New Haven, CT; 2Molecular and Cell Biology, 

University of Connecticut, Storrs, CT; 3Deaprtment of Opthalmology, 

Massachusetts General Hospital, Harvard University, Boston, MA 

Objective of the Study 

To study the interactions between olfactory receptors (OR) and odor 

molecules through molecular dynamics simulations. 

Methods 

Ten odorant ligands, eight carbon atom chain aldehydes with variable 

branches, side chains and unsaturation, were docked into the binding 

region of rat olfactory receptor I7, the first olfactory receptor identified 

by Buck & Axel in1991 and modeled by Singer (2000). The 

experimental binding of the ligands with I7 has been previously 

reported by Araneda and co-workers. (2000). We used the Singer OR 

model, and the lowest energy configuration for each docked ligand. 

Each system was first minimized, and molecular dynamics simulations 

were carried out for 500 picoseconds. 

Results 

Our results for in vacuo molecular dynamics simulations indicate that 

the ligand attempts periodically to exit and re-enter the OR binding 

region. There is an exit channel in I7 irrespective of whether the loops 

of the helical domains are included in the model. The exit events were 

strongly correlated with significant structural changes within the 

binding pocket. 

Conclusions 

The exit-reentry events may be related to the binding strengths of the 

ligands with the OR. This previously unreported exit-reentry behavior 

in OR-odor dynamics is an important consideration in the study of the 

mechanism of olfaction at the molecular level. 

Acknowledgments 

This work was supported by the Human Brain Project and the 

National Library of Medicine. 


CAN TWO NOSTRIL SNIFFING HELP ELECTRONIC NOSES? 

Johnson B.N. 1, Khan R.M. 1, Sobel N. 1 1Bioengineering, University of 

California, Berkeley, Berkeley, CA 

There is worldwide interest in development of devices to detect and 

identify airborne chemical compounds. Currently, techniques such as 

gas-chromatography and mass-spectroscopy are expensive and difficult 

to deploy in a portable package. Portable sensing devices have a wide 

range of applications such as monitoring of food and drug processing, 

manufacturing, dangerous substance identification, land mind detection, 

and medical diagnostics. However, chemical sensor technology is new 

and applications are often limited by sensor sensitivity, selectivity, 

discrimination, drift, and durability. A new theme in electronic nose 

research is to use the mammalian olfactory system as a model to 

address these issues. This direction is focusing on using multiple 

sensors and sophisticated multi-variant statistical models (PCA, 

learning machines, etc). However, there has been little attention to 

sampling technique. Often, sampling is done by flowing the carrier gas 

over the sensor or exposing the sensor to an aqueous solution 

containing the odorants. These methods are the easiest to perform, but 

may not be the most effective. In the mammalian olfactory system, 

there are two separate inputs--the left and the right nostrils. Each nostril 

receives slightly different flow rates and this results in odorants having 

different solubility characteristics between the two nostrils. In essence, 

the olfactory system receives two offset samples in a single sniff. Here 

we explore the possible benefits of using mammal-like sampling 

strategies for electronic nose technologies. 

96 


CHARACTERIZATION OF THE MECHANISM OF ODOR 

SENSING IN NOVEL DNA-BASED FLUORESCENT SENSORS. 

Williams L.B. 1, Kauer J.S. 1, White J.E. 1 1Neuroscience, Tufts 

University, Boston, MA 

Our laboratory has developed an artificial nose that exploits in 

principle, some 22 attributes of the biological olfactory system. One 

important feature is the use of broadly tuned sensor arrays to achieve 

odor detection. In the first such experiments of which we are aware, we 

show that 20-30 base single-stranded DNA-Cy3 (ssDNA) conjugates 

can respond to odorant molecules in our artificial nose. DNA-Cy3 

conjugates have the combinatorial potential to provide large arrays of 

novel sensors. The mechanism by which these sensors operate is as yet 

unknown. Preliminary work has produced a set of 9 DNA-Cy3 sensors. 

Using this sensor set, the following odorant response observations have 

been made: 1) Sensor responses return to baseline when no longer 

exposed to odorant, suggesting that the interactions between the odorant 

and the sensor are rapidly reversible and therefore non-covalent. 2) 

Change in fluorescence intensity (∆F) can be either positive or 

negative, suggesting that a simple quenching process is unlikely to be 

the mechanism. 3) Sensors tested so far (dried from water based 

buffers) do not respond as well to non-polar odorants as to polar 

odorants, and 4) Sensors do not function well at below 15% humidity 

suggesting a role for residual water (solvent). 5) Odor detection 

increases in a relatively linear manner with increasing concentration of 

odor. Based on these data, we believe that the ∆F seen in the presence 

of odors may be due to odorant molecules dissolving into the hydration 

layer surrounding the DNA and exerting solvent effects on Cy3. These 

are modulated by DNA sequence mechanisms under investigation that 

involve tertiary structure. 

Supported by grants from NIDCD and NSF. 

366 Slide [ ] Taste Genetics and Physiology 

ASSOCIATIONS BETWEEN PTC/PROP GENE, 6-N- 

PROPYLTHIOURACIL (PROP) BITTERNESS AND ALCOHOL 

INTAKE 

Duffy V.B. 1, Davidson A. 2, Kidd J. 2, Kidd K. 3, Speed W. 2, Pakstis A. 2, 

Reed D. 4, Snyder D. 5, Bartoshuk L. 5 1Dietetics Program, University of 

Connecticut, Storrs, CT; 2Genetics, Yale University, New Haven, CT; 

3Psychiatry, Yale University, New Haven, CT; 4Monell Chemical Senses 

Center, Philadelphia, PA; 5Surgery, Yale University, New Haven, CT 

Nontasters (PROP is weakly bitter) report less negative (bitterness, 

irritation) and more positive (sweet) sensations from alcoholic 

beverages than do supertasters (PROP is strongly bitter). Younger (23 

F, 26 M) and middle-aged (30 F, 5 M) adults rated bitterness of 5 PROP 

concentrations (0.032-3.2 mM) on the general Labeled Magnitude 

Scale. Alcoholic beverage intake was assessed by frequency survey; 

adults stated drinking at least once per year. DNA was analyzed for the 

PTC/PROP gene (TAS2R38) that codes for molecularly different 

receptors depending on specific amino acids at three positions in the 

protein. The common forms are AVI and PAV [Proline, Alanine, 

Valine, Isoleucine] (Kim et al, 2003). Via repeated measures analysis of 

variance (ANOVA), PROP bitterness varied significantly across 

genotype groups [AVI (n=26) less than PAV/AVI (n=38) less than 

PAV (n=22)] but not enough to explain supertasting. Age group 

(younger>middle-age) and 3.2 mM PROP bitterness (greater bitterness, 

less intake) contributed significantly to predicting alcohol intake via 

multiple regression analyses. With ANOVA, alcohol intake varied 

significantly across genotype groups (AVI>PAV/AVI>PAV) yet 

significance was primarily in younger adults. These data support taste 

genetic effects on alcohol intake. Phenotypical and genetic markers of 

taste may be necessary to study orosensory effects on diet across aging. 

(NRICGP/USDA 2002-00788, NIH DC00283, GM 57672)


GENETICS OF PTC TASTE SENSITIVITY IN HUMANS 

Drayna D. 1, Kim U. 2, Wooding S. 3, Jorde L. 4, Floriano W. 5, Goddard 

W.A. 5 1National Institute on Deafness and Other Communication 

Disor, National Institutes of Health, Rockville, MD; 2NIDCD, National 

Institutes of Health, Rockville, MD; 3Genetics, University of Utah, Salt 

Lake City, UT; 4Human Genetics, University of Utah, Salt Lake City, 

UT; 5Chemistry, California Institute of Technology, Pasadena, CA 

The inability of some individuals to taste phenylthiocarbamide (PTC) 

was discovered more than 70 years ago and since that time it has been 

the subject of detailed studies in genetics, anthropology, and sensory 

physiology. We have identified the major gene underlying this trait as 

TAS2R38, a G protein coupled bitter taste receptor located on 

chromosome 7q. The taster and non-taster forms of this protein differ at 

3 amino acid positions, and we have identified other alleles of this gene 

that encode various combinations of these 3 variant amino acids, at 

least some of which produce intermediate PTC sensitivity. We have 

used population genetic methods to study the paradoxical high 

frequency of the non-taster form of this gene. Our analyses indicate that 

both the major taster and major non-taster alleles have been maintained 

by balancing natural selection. Since bitter taste is thought to protect 

individuals from ingestion of toxic substances in our diet, this raises the 

question of what selective benefit is provided by the non-taster allele. 

We hypothesize that the non-taster form of the protein serves as a 

functional receptor for a different toxic bitter substance not yet 

identified. We have also employed molecular structure prediction 

techniques to determine the 3D structure of the taster and non-taster 

forms of this receptor, along with PTC ligand binding sites. Our results 

indicate that PTC binds to both forms of the receptor with equal 

affinity, and that the non-taster form of the protein does not signal due 

to a failure of G protein activation. 

Supported by NIDCD/NIH Z01-000046 (to D.D.), by NIH grants 

ES12125 (to S.W.), GM59290 (to L.J.), and NSF grant BCS0218370 

(to L.J.) 

97 


GENETIC CONTROL OF LICK RATE IN MICE 

Boughter J. 1, St. John S. 2, Williams R.W. 3, Lu L. 1 1Anatomy & 

Neurobiology, University of Tennessee, Memphis, TN; 2Psychology, 

Reed College, Portland, OR; 3Anatomy and Neurobiology, University of 

Tennessee, Memphis, Memphis, TN 

Licking is a highly stereotyped behavior that is thought to be 

determined in part by a central pattern generator (CPG). Lick rate has 

been shown to differ among inbred strains of mice, and may play a role 

in apparent differences in gustatory sensitivity. We used a 20 minuteaccess 

procedure to quantify lick rate in several strains of waterdeprived 

mice. Inbred strains could be classified as fast, intermediate, 

or slow lickers based on the median value of the inter-lick interval (ILI) 

distribution. With virtually no overlap among individual distributions, 

C57BL/6J (B6; n = 36) mice were classified as slow lickers (average 

median ILI = 122.8 ms) whereas DBA/2J (D2; n = 27) mice were fast 

lickers (average median ILI = 101.1). Mice from an F1 generation (n = 

14) possessed an intermediate phenotype (112.8 ms). Fast / slow lick 

rate phenotypes were static over an extended time period, and were also 

evident in non-deprived tests with sucrose. Further testing of an F2 

generation (n = 62) resulted in an estimate of broad-sense heritability = 

0.54, with no fewer than 2 polymorphic genes influencing the ILI 

phenotype. Initial QTL mapping analysis using a panel of BXD RI 

strains indicates that at least two and possibly as many as 4 QTL with 

comparatively large effects on the ILI are segregating in this cross. 

These data will soon be complemented with a genome scan of a panel 

of ~ 150 F2 mice that are now being typed using a panel of ~70 

microsatellite markers. Additionally, we show how differences in lick 

rate between B6 and D2 strains may exert a non-gustatory influence in 

lick ratio measurements of sucrose sensitivity. Supported by 

DC004935(JDB). 


INTAKE OF SWEET AND BITTER SOLUTIONS: VARIATION 

IN INBRED STRAINS OF GOLDEN HAMSTERS 

Frank M.E. 1, Wada Y. 2, Makino J. 2, Mizutani M. 2, Umezawa H. 3, 

Katsuie Y. 3, Hettinger T.P. 1, Blizard D.A. 4 1Oral Diagnosis, 

Neurosciences, UCONN Health Center, Farmington, CT; 2Institute of 

Psychology, University of Tsukuba, Tsukuba, Ibaraki, Japan; 

3Laboratory Animal Research Station, Nippon Institute for Biological 

Science, Kobuchizawa, Yamanashi, Japan; 4Pennsylvania State 

University, University Park, PA 

Intake of sweet and bitter solutions by 7 inbred strains of golden 

hamsters (Mesocricetus auratus), a principal species for studies of 

mammalian gustatory systems, was measured. Two concentrations of 

sucrose, maltose, D-Phe and Na saccharin, which are sweet; and 

quinine·HCl, L-Phe, caffeine and sucrose octaacetate (SOA), which are 

bitter to humans, were tested. Difference scores, solution intake minus 

mean baseline water intake in mL (DIF), were evaluated by analysis of 

variance (α = .05). Compared to ACN, CN, APA, APG and CBN (5 

strains with similar DIF for all tested solutions), the strains ACNT and 

GN (an ACNT ancestral strain) preferred sucrose, caffeine and SOA 

more strongly; ACNT also preferred saccharin and maltose more 

strongly and rejected quinine more strongly. There were no strain 

differences in DIF for D-Phe or L-Phe. Narrow sense heritabilities for 

the 6 compounds for which strain differences were revealed ranged 

from 0.31 to 0.57. Genetic correlations indicated the strain variations in 

intake of sucrose, saccharin, SOA and caffeine were coupled, 

suggesting an association with several possible interpretations. The 

genetic differences that influence taste behaviors in existing strains of 

hamsters may help identify relevant genes. [Supported by NIH grant 

R01 DC04099 (MEF) and a Japan Society Senior Fellowship (DAB)]


RESPONSES TO ETHANOL IN WILD TYPE (WT) AND - 

GUSTDUCIN KNOCKOUT (KO) MICE 

Danilova V. 1, Danilov Y. 1, Damak S. 2, Margolskee R. 2, Hellekant G. 1 

1Animal Health and Biomedical Sciences, University of Wisconsin- 

Madison, Madison, WI; 2Physiology and Biophysics, Mount Sinai 

School of Medicine, New York, NY 

Although it has been shown that C57Bl/J mice prefer ethanol, it is 

not known what kind of taste nerve responses ethanol elicits. We have 

shown in primates that ethanol stimulates chorda tympani (CT) and 

glossopharyngeal (NG) taste fibers and the response depends on type of 

taste fibers. Our purpose was to study taste responses to ethanol in 

mice. We also investigated if α-gustducin is involved in transduction of 

ethanol taste. 

Methods. CT and NG responses and results of two bottle preference 

tests (TBP) with ethanol (0.5-5 M) were recorded in WT and KO mice. 

Results. 1. In WT only high concentrations of ethanol elicited CT 

responses. This contrasts NG effects in which low concentrations 

elicited significant responses. 2. In both nerves the responses developed 

slowly. 3. In KO ethanol did not produce CT responses at any 

concentration. The NG responses did not differ between the two groups. 

4. In contrast to WT, KO did not prefer ethanol at any concentration 

and rejected higher concentrations in TBP tests. 

Conclusion. Ethanol is not an effective stimulus in WT mice in 

contrast to primates. Absence of preference and CT responses to 

ethanol together with previously demonstrated decrease of responses to 

sweeteners in KO mice suggest that ethanol has a sweet taste 

component, which may be the cause for its consumption by WT. Thus 

α-gustducin is important in transduction of ethanol taste and 

consumption. Rejection of ethanol by the KO might be explained by the 

significant responses in the NG, which may originate from non-taste 

fibers or non-sweet fibers. 

Supported by NIH DC 03155 and NIH DC005336 

371 Slide [ ] Pheromones 

A DROSOPHILA ODORANT-BINDING PROTEIN MEDIATES 

RESPONSES TO A PHEROMONE 

Smith D. 1, Xu P. 1, Atkinson R. 2, Jones D. 3 1Pharmacology, University 

of Texas Southwestern Medical Center at Dallas, Dallas, TX; 

2Phamacology, University of Texas Southwestern Medical Center at 

Dallas, Dallas, TX; 3Pharmacology, University of Colorado Health 

Sciences Center, Denver, CO 

Pheromones are chemosensory cues released by animals to influence 

the behavior of other members of the same species. In Drosophila, a 

male-specific lipid, 11-cis vaccenyl acetate (VA), mediates olfactorybased 

social aggregation. OBPs are a large family of proteins found in 

all terrestrial species and have been suggested to transport odorants. 

Here we show that the odorant binding protein 76a (OBP76a), an 

extracellular protein secreted into the fluid bathing a subset of olfactory 

neurons, is required for behavioral attraction to VA. This phenotype is 

due to a complete loss of VA-evoked activity in pheromone sensitive 

neurons. These defects are reversed by germline transformation with a 

cloned, wildtype copy of obp76a or, importantly, by introducing 

recombinant OBP76a protein into mutant sensilla. Remarkably, 

spontaneous activity of the pheromone-sensitive neurons is reduced 

over 400-fold in the absence of the binding protein. This implicates the 

binding protein as a direct activator of the pheromone-sensitive 

neurons. These studies directly link odorant binding protein expression 

with activation of a specific subset of olfactory neurons and 

pheromone-induced behavior. We suggest OBP76a is an extracellular 

modulator of neuronal activity that translates the presence of 

pheromone to neuronal activation. 

98 


PHEROMONE REGULATION OF A TRANSCRIPTION 

FACTOR IN THE HONEY BEE BRAIN 

Grozinger C.M. 1, Robinson G.E. 2 1Department of Entomology, 

Program in Neuroscience, University of Illinois at Urbana-Champaign, 

Urbana, IL; 2Department of Entomology; Program in Neuroscience, 

University of Illinois, Urbana-Champaign, Urbana, IL 

Christina M. Grozinger*‡ and Gene E. Robinson‡ 

*Beckman Institute for Advanced Science and Technology 

‡Department of Entomology 

‡Program in Neuroscience 

University of Illinois, Urbana-Champaign 

Honey bee social organization is predominantly regulated by 

chemical communication. Using honey bee cDNA microarrays, we 

have begun to analyze the molecular mechanisms of pheromonal 

regulation of honey bee behavior by using queen mandibular 

pheromone (QMP), one of the primary pheromonal regulators of 

physiology and behavior of worker bees. One of the genes QMP 

regulates in the bee brain is the transcription factor, Kr-h1. Kr-h1 is 

expressed primarily in the mushroom bodies, the region of the insect 

brain associated with multimodal integration and learning, and its 

expression is regulated by QMP especially strongly in this region. 

Furthermore, Kr-h1 expression is correlated with foraging in bees, and 

seems to be activated prior to the transition to the foraging behavioral 

state. Previous work has demonstrated that honey bee mushroom 

bodies undergo a period of synaptic remodeling and expansion prior to 

the initiation of foraging, and synaptic remodeling continues as bees 

gain foraging experience. The specific localization and timing of Kr-h1 

expression suggests that it may be involved in this process. 

Supported by a Beckman Institute Postdoctoral Fellowship to CMG, 

and grants from the Burroughs Welcome Trust, NIH, and USDA to 

GER


CHEMICAL COMMUNICATION IN ZEBRAFISH: HOW 

PHEROMONES AFFECT FEMALE MATE CHOICE 

Gerlach G. 1 1Marine Resources Center, Marine Biological Laboratory, 

Woods Hole, MA 

In contrast to males, female fitness can decrease significantly by 

inappropriate matings. In species in which females usually receive no 

resources from a male besides his sperm, females might choose mating 

partners whose genes will confer greater fitness on her offspring. While 

several studies have shown how pheromones trigger and synchronize 

mating behavior in fish very little is known if pheromones can be used 

as signals to assess mate quality. In odor choice tests we analyzed the 

olfactory preference of female zebrafish for a) males of different 

relatedness and b) males of different social rank. 

A single female zebrafish was exposed to stimulus water of different 

males on either side of a flume. The time a female spent on either side 

was determined. As odor stimuli holding water of males were used that 

were either related (brother) or unrelated to the female. In the second 

experiment two male zebrafish were isolated in a 9 l tank and observed 

for agonistic interactions. After two days the dominant and subordinate 

male were separated in single tanks and their holding water was used as 

stimuli. 

The results can be summarized as follows: 1) Adult females preferred 

the odor of unrelated males. 2) Females preferred odor cues of 

dominant over subordinate males. 

We conclude that kin recognition mechanisms such as phenotype 

matching occur in zebrafish that enables females to avoid inbreeding. In 

addition, dominant males seem to release a specific odor cue that made 

them distinguishable from subordinate males. 

Our successful breeding of a zebrafish mutant without a nose and an 

olfactory bulbus provides a unique opportunity for further analyses of 

the effect of pheromones on mate choice. 

374 Slide [ ] Olfactory Development, Disease, and Plasticity 

IT CAME FROM THE SEA – OLFACTORY ADAPTATIONS 

FOR A TERRESTRIAL LIFE IN THE ROBBER CRAB (BIRGUS 

LATRO) 

Stensmyr M.C. 1, Erland S. 2, Greenaway P. 3, Hansson B.S. 1 1Swedish 

University of Agricultural Sciences, Alnarp, Sweden; 2Ecology, Lund 

University, Lund, Sweden; 3Biological Sciences, University of New 

South Wales, Sydney, New South Wales, Australia 

An important step in the evolution of the olfactory sense has been the 

transition from sea to land. Although terrestrial and aqueous olfactory 

systems share many characteristics, marked differences exist. These 

distinctions likely reflect the differences of the ligands that the systems 

need to detect, air borne, mostly hydrophobic volatiles on land and 

water-soluble molecules in the sea. The olfactory system of land crabs, 

whose terrestrial existence is a comparatively recent evolutionary 

development, represents an excellent opportunity to investigate the 

effects of the sea to land transition. Have land crabs come to the same 

solutions as other terrestrial animals, or is their olfactory sense 

characterized by unique innovations? Here we show that the terrestrial 

robber crab (Birgus latro) have evolved an olfactory sense displaying a 

high degree of resemblance to the insect system. The similarities extend 

to physiological, behavioural and morphological characters. The insect 

nose of the robber crab is a striking example of convergent evolution, 

and nicely illustrates how similar requirements result in similar endproducts. 

99 


EXAMINATION OF CIRCADIAN RHYTHMS IN THE 

ANTENNA OF THE MOTH MANDUCA SEXTA 

Stengl M. 1, Flecke C. 2, Schuckel J. 2, Siwicki K.K. 3 1University of 

Marburg, Marburg, Germany; 2Biology, Philipps-University of 

Marburg, Marburg, Germany; 3Biology, Swarthmore College, 

Swarthmore, PA 

A coupled network of circadian pacemakers orchestrates 

physiological processes in a 24 h rhythm. In Drosophila melanogaster 

circadian pacemakers in the antenna contain the circadian protein 

PERIOD (PER) and appear to drive 24 h rhythms of olfactory 

sensitivity. In the hawkmoth Manduca sexta a circadian rhythm of 

octopamine was measured in the hemolymph and octopaminergic 

neurons project into the antenna. Because octopamine is known to 

sensitize pheromone-perception in different moths apparently via 

cAMP-dependent mechanisms we wanted to know whether this also 

applies to the night-active M. sexta. In addition, we tested whether also 

in M. sexta olfactory receptor neurons (ORNs) are PERimmunoreactive. 

In extracellular tip-recordings from single sex-pheromone-dependent 

ORNs responses to the pheromone-component bombykal were tested 

under constant light at two different time points with or without the 

presence of 8bromo-cAMP in the recording electrode. During control 

recordings pheromone-dependent action potential responses showed a 

decline from ZT 1-4, but not at ZT 8-11. This decline was not seen in 

the presence of 8bromo-cAMP. Thus, possibly circadian adaptation of 

the action potential generator occurs during the day which is 

counteracted by octopamine-dependent cAMP-rises at night. Antibodies 

against the circadian clock protein PER stained ORNs and other 

antennal cells. Future studies examine whether PER-antibodies delete 

the circadian decline in the sensitivity of ORNs.[Supported by DFG 

grant STE531/13-1 to M.S.]


LIFE STAGE AND ODORANT-INDUCED CHANGES IN 

OLFACTORY SENSITIVITY IN COHO SALMON, 

ONCORHYNCHUS KISUTCH 

Dittman A. 1, May D. 2, Baldwin D. 3, Scholz N. 3 1Northwest Fisheries 

Science Center; NOAA-Fisheries, Seattle, WA; 2School of Aquatic and 

Fishery Science, University of Washington, Seattle, WA; 3Northwest 

Fisheries Science Center, Seattle, WA 

Over the lifetime of an organism, the sensitivity of the olfactory 

system to specific odors may change in response to developmental 

changes, hormones, environmental stimuli, and odorant exposure. 

Salmon provide an excellent model for studying such changes because 

almost every aspect of their lives is influenced by olfaction and they 

experience dramatic developmental and environmental transitions 

(smolting, maturation, freshwater vs. oceanic) as part of their 

migrations from freshwater to oceanic feeding grounds and back. 

Furthermore, these homing migrations are governed by olfactory 

discrimination of home stream odors that juvenile salmon learn (imprint 

to) prior to their seaward migrations. Our previous studies demonstrated 

that salmon imprinted to the odorant phenylethyl alcohol (PEA) 

developed a long-term sensitization of peripheral olfactory neurons to 

this odorant. To further examine this imprinting phenomenon, we 

exposed juvenile coho salmon, Oncorhynchus kisutch to three distinct 

classes of odorants (amino acids, bile acids and PEA) during smolting, 

the presumptive sensitive period for imprinting. To assess life stage and 

olfactory imprinting associated changes in the sensitivity of the 

olfactory system, we recorded electrical field potentials (electroolfactograms) 

generated in response to these three classes of odorants 

and ovarian fluid at four distinct life stages: oceanic juvenile, maturing 

adult , immature adult, and mature. Our results suggest that olfactory 

sensitivity changes over the lifetime of the salmon and previous odor 

exposure can influence olfactory responses. 

Funded by BPA Grant #199305600 


DEFECTIVE OLFACTORY DEVELOPMENT IN 3GNT1 NULL 

MICE 

Schwarting G. 1, Raitcheva D. 2, Hennet T. 3, Henion T. 1 1University of 

Massachusetts Medical School (Worcester), Waltham, MA; 2Shriver 

Center, Waltham, MA; 3University of Zurich, Zurich, Switzerland 

Subsets of olfactory neurons in mice express unique lactosamine 

containing glycans (LCGs) that reacts with the monoclonal antibody, 

1B2. We have previously shown that LCGs are expressed by neurons in 

all zones of the embryonic OE but project axons preferably to the 

ventral OB, suggesting that this glycan may participate in axon 

guidance mechanisms. The gene encoding an enzyme critical for 

synthesis of LCGs was recently isolated. In situ hybridization reveals 

that this enzyme, β1-3-N-acetylglucosaminyltransferase-1 (β3GnT-1) is 

expressed by neurons in the OE beginning at very early embryonic 

stages. We show here that mice deficient in β3Gnt-1 fail to express 

LCGs during embryonic and early postnatal olfactory development. 

β3Gnt-1 null mice have severe defects in formation of connections 

between the OE and OB at birth. Between P1 and P10, many OMP+ 

glomeruli are absent from the glomerular layer of the OB of β3GnT-1 

null mice. This defect in glomerulogenesis is accompanied by increased 

neuronal cell death in P1 mice followed by an increase in neurogenesis 

at P10. In addition, the expression of some odorant receptors, such as 

P2, are significantly down-regulated in β3Gnt-1 null mice. Although 

OBs of β3GnT-1 null mice are about 25% smaller than control 

littermates, overall structure and layering of these OBs is relatively 

normal. In summary, mice that do not express LCGs in the embryonic 

and early postnatal OE fail to form normal axonal connections with the 

OB, suggesting that LCGs play an important role in axon growth and 

guidance in the developing mouse olfactory system. Supported by 

DC00953. 

100 


EFFECT OF AIR POLLUTION ON OLFACTORY FUNCTION 

IN RESIDENTS OF MEXICO CITY 

Hudson R. 1, Arriola A. 1, Martínez-Gómez M. 2, Distel H. 3 1Inst. Biomed. 

Res., Univ. Nacional Autónoma de México, Mexico City, Mexico; 

2Centro Tlaxcala Biol. Conducta, Univ. Autónoma de Tlaxcala, 

Tlaxcala, Mexico; 3Inst. Med. Psychol., Univ. München, München, 

Germany 

To our knowledge there has been no study of the effect of everyday 

air pollution on olfactory function. It was therefore the aim of this study 

to compare the olfactory performance of long-term residents of Mexico 

City (MC) - an environment with high air pollution, with the olfactory 

performance of residents of the Mexican state of Tlaxcala (Tx) - a 

region culturally and geographically similar to MC but with low air 

pollution. Healthy volunteers (MC n = 82, Tx n = 86) from 20-63 years 

of age and balanced for gender were tested for the perception of the 

odors of everyday beverages presented in squeeze bottles. When tested 

with ascending concentrations of stimuli in a 3-way oddball paradigm, 

residents of Tx detected the odor of an orange juice preparation (Clight) 

and of Nescafe at significantly lower concentrations than residents of 

MC. They could also attribute a quality to and then finally correctly 

identify the stimuli at lower concentrations. However, differences 

between the groups decreased across the three tasks, suggesting the 

increasing participation of central, cognitive processes unimpaired by 

pollution. Residents of Tx also performed significantly better in 

discriminating between the two similarly smelling Mexican beverages 

of horchata and atole in oddball tests. Significant differences between 

the two populations were apparent even in the youngest subjects. No 

significant differences were found between sexes. Thus, air pollution in 

Mexico City appears to have a substantial impact on peripheral 

olfactory function, even in young adults. 


OLFACTORY DYSFUNCTION OCCURS IN TRANSGENIC 

MICE OVEREXPRESSING HUMAN TAU PROTEIN 

Doty R.L. 1, Macknin J. 2, Kerr K. 3, Higuchi M. 4, Lee V. 5, Trojanowski 

J. 5 1Smell and Taste Center, Department of Otorhinolaryngology: Head 

& Neck Surgery, University of Pennsylvania, Philadelphia, PA; 2Smell 

& Taste Center, Department of Otorhinolaryngology: Head & Neck 

Surgery, University of Pennsylvania, Philadelphia, PA; 3Smell & Taste 

Center, Department of Otorhinolaryngology: Head and Neck Surgery, 

University of Pennsylvania, Philadelphia, PA; 4Laboratory for 

Proteolytic Neuroscience, Riken Brain Science Institute, Saitama, 

Japan; 5Center for Neurodegenerative Disease Research, University of 


Disorders of olfaction are among the first clinical signs of 

neurodegenerative diseases such as Alzheimer´s disease (AD) and 

idiopathic Parkinson´s disease (PD). In this study, we evaluated the 

olfactory function of Ta1-3RT transgenic mice that overexpress tau, a 

key pathogenic protein in AD, and compared such function to that of 

wild type controls who do not express this protein. The Ta1-3RT mice, 

but not the controls, exhibited responses indicative of decreased 

olfactory function. These data (a) lend support to the notion that tau 

may be involved in the pathogenesis of the olfactory dysfunction of 

some neurodegenerative diseases and (b) demonstrate, for the first time, 

that olfactory function is present in a transgenic mouse model of 

neurodegenerative tauopathies including the filamentous tau tangles 

seen in AD. Future studies need to similarly assess other pathogenic 

markers, as well as their distribution within various sectors of the brain, 

to determine the specificity of this phenomenon. 

Supported, in part, by the following grants from the National 

Institure of Health, Bethesda, MD: RO1 DC 04278, RO1 DC 02974, 

RO1 AG 17496 and PO1 AG 11542.


PREDATOR AND NON-PREDATOR ODORS: SIMILARITIES 

IN SPECTRAL AND BEHAVIORAL PATTERNS 

Lowry C.A. 1, Kay L.M. 2 1Neurobiology, University of Chicago, 

Chicago, IL; 2Psychology, University of Chicago, Chicago, IL 

Previous research has suggested that olfactory structures respond to 

predator odors with bursts of oscillatory activity in the beta frequency 

band (15-40Hz). However, those same oscillation bursts were seen in 

response to some non-predator odors. We compare physiological and 

behavioral responses to six monomolecular odorants (toluene, amyl 

acetate, benzaldehyde, acetone, indole, vanillin) with responses to two 

predator odors (trimethyl thiazoline [TMT] and fox urine). Olfactory 

bulb (OB) local field potential (LFP) responses were recorded during 

five consecutive 2-minute presentations of odorants in a closed 

chamber, and behavior was recorded by webcam. Theta (3-15 Hz), beta 

(15-40Hz), low gamma (35-60Hz), and high gamma (60-115Hz) 

oscillation patterns are examined in response to each odor. We find 

similarities between predator and non-predator odors across frequency 

bands, as well as some differences between the two predator odors 

tested. Behavioral responses, such as freezing and attentive sniffing, are 

strongly correlated with concurrent oscillatory activity. Our results 

suggest that variations in oscillatory patterns can be attributed primarily 

to behavioral variations. We also find that isoamyl acetate (IAA) 

produces frequency responses different from all the other 

monomolecular odors tested. This suggests that IAA, which is used as a 

control odor in many olfactory studies, may be inappropriate for this 

purpose. 

Support: Brain Research Foundation Fay/Frank Seed Grant 

381 Poster [ ] Cell Biology of the Olfactory Epithelium 

TYROSINE HYDROXYLASE PROMOTER-DRIVEN 

REPORTER GENE EXPRESSION IN OLFACTORY 

EPITHELIUM OF TRANSGENIC MICE 

Sasaki H. 1, Berlin R. 1, Baker H. 1 1Burke Med. Res. Inst., Weill Med. 

Coll., Cornell Univ., White Plains, NY 

Transgenic mice expressing either green fluorescent protein (GFP) or 

lacZ reporter genes driven by 9kb of tyrosine hydroxylase (TH) 

promoter have been extensively used in characterizing the CNS 

dopaminergic phenotype. To investigate whether TH promoter driven 

reporter gene expression occurred in the olfactory epithelium (OE), 

TH/GFP and TH/lacZ transgenic mouse strains were examined using 

immunohistochemical or X-gal histochemical methods. The antibodies 

used were chicken anti-GFP, rabbit anti-TH, rabbit anti-βgal and goat 

anti-olfactory marker protein (OMP). Both GFP-immunoreactive (IR) 

and βgal-IR cells localized to the superficial OE. The cells showed a 

sparse distribution that was similar to the zone 1 pattern of olfactory 

receptor neurons (ORN). Morphologically, the cells resembled ORNs 

with a dendritic and an axonal process directed towards the nasal cavity 

and the lamina propria, respectively. Axonal processes did not enter the 

OB. Double label confocal analysis showed that OMP, a marker of 

mature ORNs, was not coexpressed with either GFP or βgal. X-gal 

staining confirmed the cellular morphology and distribution of the 

transgene expressing cells in the OE. The vomeronasal organ contained 

a few βgal-IR cells. Reporter gene expression was negatively correlated 

with age with cell number highest at postnatal day 2 (P2), the first age 

examined, and declining until few cells could be detected at P22. These 

studies suggest that some cells in the OE transiently exhibit low level 

expression of dopaminergic properties during early postnatal 

development. (Supported by grant #AG09686) 

101 


THE FINE STRUCTURAL DISTRIBUTION G-PROTEIN 

RECEPTOR KINASE 3 (GRK3), &BETA-ARRESTIN-2, 

CA++/CALMODULIN-DEPENDENT PROTEIN KINASE II 

(CAMKII), AND PHOSPHODIESTERASE PDE1C2 IN 

OLFACTORY EPITHELIA 

Menco B. 1 1Neurobiology and Physiology, Northwestern University, 

Evanston, IL 

The sequentially activated molecules of olfactory signaling onset are 

mostly concentrated in the long thin distal parts of olfactory epithelial 

(OE) receptor cell (ORC) cilia (Chem Senses 22:295,1997). Is this also 

true for the sites of signal termination? GRK3 is thought to act at the 

level of the odor receptors, whereas &beta-arrestin-2, CAMKII, and 

PDE1C2 are thought to act at the level of adenylyl cyclase. We used 

four antibodies to GRK3, two to &beta-arrestin-2 (one, courtesy Dr. 

Lefkowitz, Duke Univers.), five to CAMKII (one to both the &alpha 

and &beta form, and two each specific to &alpha- and &beta- 

CAMKII), and two to PDE1C2 (courtesy Dr. Beavo, Univers. of 

Washington). Earlier, light microscopic, studies showed that antibodies 

to all of these molecules labeled the OE luminal border that includes 

ORC cilia (Science, 259:825,1993; J Biol Chem 41:25425,1997; 

Neuron 21:495,1998; Proc Natl Acad. Sci USA 94:3388,1997). 

However, the current, fine structural, data indicate that none of these 

antibodies labeled ORC cilia exclusively, and included other ORC 

structures, such as dendritic endings, as well. Significantly, the 

antibodies also labeled apices and microvilli of neighboring OE 

supporting cells and some bound to luminal regions, including cilia, of 

the respiratory epithelium adjacent to the OE. Thus, among others, the 

observations suggest that neuronal ORCs and neighboring OE 

supporting cells share at least some molecules of signal transduction. In 

the supporting cells, these molecules occur in addition to those of 

biotransformation and transepithelial transport. Supported by NSF 

Grant IBN-0094709. 


IMMUNOCYTOCHEMICAL LOCALIZATION OF 11 BETA- 

HYDROXYSTEROID DEHYDROGENASE IN THE 

MAMMALIAN OLFACTORY MUCOSA 

Foster J.D. 1, Sullivan D. 1 1Anatomy, Western University of Health 

Sciences, Pomona, CA 

Mineralocorticoid (type I) receptors have been identified in the 

olfactory mucosa by a number of approaches. In immunohistochemical 

studies, mineralocorticoid receptor immunoreactivity was localized to 

the supranuclear region of sustentacular cells, as well as the acinar cells 

of the Bowman's glands. Functioning of the mineralocorticoid (type I) 

receptor is enhanced by the action of the enzyme 11 betahydroxysteroid 

dehydrogenase type II (11 beta HSD2). 11-beta HSD2 

catalyses the inactivation of glucocorticoids, thus playing a major role 

in the protection of the mineralocorticoid (type I) receptor. In previous 

studies using histochemical and biochemical approaches, 11 beta HSD 

was identified in the olfactory mucosa. The objective of this current 

study was to identify the corticosteroid inactivating (type II) form of the 

11 beta HSD by use of a monoclonal antibody specific to 11-beta 

HSD2. When we incubated sections from the olfactory mucosa with 

this antibody, 11 beta HSD2 immunoreactivity was found associated 

with the acinar cells of Bowman´s glands and the supranuclear region 

of sustentacular cells. This distribution corresponds with the location of 

mineralocorticoid (type I) receptors reported in earlier studies and the 

histochemical location of 11 beta HSD. This study provides further 

evidence that mineralocorticoid hormones may be involved in the 

modulation of olfactory function. Supported by Western University 

College of Osteopathic Medicine of the Pacific Summer Research 

Program


LOCALIZATION OF RETINOIC ACID RECEPTORS IN 

MOUSE AND HUMAN NASAL EPITHELIUM 

Yee K.K. 1, Hahn C. 2, Rawson N.E. 1 1Monell Chemical Senses Center, 

Philadelphia, PA; 2Dept. Psychiatry, University of Pennsylvania, 


All-trans retinoic acid (ATRA), a metabolite of vitamin A, binds to 

retinoic acid receptors (RARs) to mediate gene-transcription in target 

cells. We previously found that an ATRA supplement enhanced 

olfactory recovery rate in adult mice after olfactory bulb (OB) 

deafferentation. In this study, we examined the localization of 

RAR&alpha, RAR&beta, and RAR&gamma after injury and ATRA 

treatment using immunocytochemistry. Mice received a left olfactory 

nerve transection (LNX) with the right side serving as control. One day 

after LNX, the mice were given either ATRA mixed with sesame oil or 

just sesame oil. In the control OB, RAR&alpha immunoreactivity (ir) 

was observed in periglomerular and granule cells, while we did not 

detect immunostaining for RAR&beta or RAR&gamma. In the oiltreated 

right olfactory epithelium (OE), RAR&alpha -ir was found in 

NST- and SUS4-negative microvillar-like cells located in the 

supporting cell layer, in cells in the lamina propria, and in some 

respiratory cells. RAR&beta -ir was localized only in the respiratory 

cells while no RAR&gamma -ir was observed in the OE. Surprisingly, 

the density of RAR&alpha -ir microvillar-like cells was higher in the 

transected OE and highest in transected OE with ATRA treatment, 

suggesting these cells are non-neural. We also examined RARs-ir in 

human nasal tissue and found a similar cellular localization. These 

findings suggest that microvillar cells, a population about which 

comparatively little is known, are targets for ATRA modulation of gene 

expression in the OE and may play a role in OE recovery following 

injury. Supported by NIH DC04645 and DC00214. 


IMMUNOLOCALIZATION OF BEX PROTEINS IN THE 

MOUSE BRAIN: COLOCALIZATION WITH OMP 

Koo J. 1, Manda S. 1, Margolis F.L. 1 1Medicine, University of Maryland 

at Baltimore, Baltimore, MD 

Bex proteins are a family of “Brain expressed X-linked genes” that 

are closely linked on the X-chromosome. Bex1 and 2 have been 

characterized as interacting partners of OMP. Here we report the 

development and characterization of an antibody to mouse Bex1 protein 

that also cross-reacts with Bex2 (but not Bex3) and its use to determine 

the first comprehensive distribution of Bex proteins in the murine brain. 

Immuno-blots and immunocytochemical analyses of cells transfected 

with either Bex1 or Bex2 have shown that the antiserum reacts with 

both Bex1 and Bex2. Antibodies preabsorbed with recombinant Bex2 

still recognize Bex1 while blocking with Bex1 totally eliminates all 

immunoreactivity to Bex1 and Bex2. Bex protein immunoreactivity (ir) 

was primarily localized to neuronal cells within select regions of the 

brain, including the olfactory bulb, epithelium, peri/paraventricular 

nuclei, suprachiasmatic nucleus, arcuate nucleus, median eminence, 

lateral hypothalamic area, thalamus, hippocampus, and cerebellum. Bex 

protein-ir was broadly present throughout the rostral-caudal aspects of 

the hypothalamic region. Further studies, using double-label 

immunocytochemistry, indicate that Bex-ir is colocalized with OMP in 

mature ORNs and in the OMP-positive subpopulation of hypothalamic 

neurons. This is the first anatomical demonstration of the 

comprehensive mapping of Bex proteins in the mouse brain and their 

colocalization with OMP in ORNs and hypothalamic neurons. 

Supported by NIH grants DC003112 and DC00054. 

102 


REDUCED OLFACTORY EPITHELIUM MITOTIC RATE IN 

STREPTOZOTOCIN-INDUCED DIABETIC RATS 

Dennis J.C. 1, Swyers S. 2, Wright J.C. 3, Coleman E.S. 4, Judd R.L. 2, Hoe 

L. 2, Morrison E.E. 4 1Anatomy, Physiology and Pharmacology, Auburn 

University, Auburn, AL; 2Anatomy, Physiology, Pharacology, Auburn 

University, Auburn, AL; 3Pathobiology, Auburn University, Auburn, 

AL; 4Anatomy, Physiology, Pharmacology, Auburn University, Auburn, 

AL 

Individuals who suffer from diabetes frequently develop anosmia for 

unknown reasons. The site(s) of disfunction in the olfactory pathways is 

(are) not known. We used immunohistochemistry to compare the 

numbers of mitotically active cells in the main olfactory epithelium 

(OE) of normal (n=4) male Wistar rats and in males (n=4) that suffered 

from streptozotocin (STZ)-induced diabetes. Insulin-dependent (type 1) 

diabetes was induced by intravenous injection of 50 mg/kg bw STZ. 

After 8 weeks, each animal was injected with bromodeoxyuridine 

(BrdU) (50ìg/gm bw). An hour later, the animals were deeply 

anesthetized with pentobarbital and perfused with buffered 4% 

paraformaldehyde. After paraffin embedding, 7 ìm transverse sections 

were mounted on slides and hydrated. BrdU(+) cells were counted in 8 

nonserial sections from 3 regions dorsal to ventral per animal. The 

length of epithelium containing those cells was measured using Spot 

Advanced software. Counts were rendered as BrdU(+) cells/mm 

epithelium. Analysis by Student´s t Test using SAS 8.2 software 

indicated a significant difference in mitotic rates (p0.05). 

These data indicate that, after 8 weeks of STZ-induced type 1 diabetes 

in Wistar rats, mitotic rate in the main OE is lower in diabetics 

compared to normal controls. 


QUALITATIVE AND QUANTITATIVE STUDY OF 

CYTOCHROME OXIDASE STAINING PATTERN IN 

OLFACTORY EPITHELIUM OF NEONATAL RAT 

Pataramekin P.P. 1, Meisami E. 1 1Molecular and Integrative Physiology, 

University of Illinois at Urbana-Champaign, Urbana, IL 

Newborn rats are capable of olfaction and their olfactory epithelium 

(OE) contains functionally mature olfactory receptor neurons (ORNs), 

although total ORN number is less than 10% of adult. Cytochrome 

oxidase (CO) staining density is positively correlated to levels of 

metabolic/neuronal activity. We stained newborn rat OE to characterize 

its staining pattern qualitatively and quantitatively. Staining 

densitometry was carried out using MCID software to gauge the 

luminescence of the sample over a range of 0.0 – 1.0 (higher numbers 

indicated lesser CO staining). A differential banding pattern of CO 

staining was observed corresponding to specific OE layers and ORN 

cellular sites, indicating the parts of the ORNs that were most actively 

involved in neuronal activity and transduction. Zones corresponding to 

ORN dendrite and knob exhibited high CO activity (0.34). Staining was 

heterogeneous within and along the length of dendrites, darker in the 

apical part, implying higher neuronal activity in this region than the 

deeper part of the dendrite, closer to the soma. A light staining band 

(0.40), between the two dark bands, corresponded to the overlapping 

presence of supporting cell cytoplasm and nuclei. Areas of OE close to 

the basal lamina also stained lightly (>0.44), implying lack of 

mitochondria and neuronal functional activity in the basal and immature 

neurons. The findings confirm that some ORNs are metabolically 

mature and functional in neonatal rats, capable of neuronal function. 

Support: University of Illinois Research Funds


FUNCTIONAL CHARACTERIZATION OF CUB-SERINE 

PROTEASE IN THE SPINY LOBSTER'S OLFACTORY ORGAN 

Johns M. 1, Tai P. 1, Derby C.D. 1 1Biology, Georgia State University, 

Atlanta, GA 

Several serine proteases and protease inhibitors have been identified 

in the olfactory organ of decapod crustaceans (Hollins et al., 2003, J 

Comp Neurol 455:125-138; Stoss et al., 2002, Chem Senses 27:A45) 

including a CUB-serine protease (Csp: Levine et al., 2001, J Neurobiol 

49:277-302). The function of these proteases in the olfactory organ is 

unknown. To examine directly the functional activity of proteases in 

the olfactory organ of the Caribbean spiny lobster Panulirus argus, we 

used soluble and membrane tissue fractions from the lateral flagellum 

in a spectrophotometric enzyme activity assay with a variety of protease 

substrates and inhibitors to demonstrate trypsin-like serine protease 

activity. Csp accounts for at least 40% of the serine protease activity of 

the membrane fraction of the olfactory organ, based on 

immunoprecipitation of Csp. Serine protease activity follows a 

developmental pattern: it is lowest in the proximal zone, which lacks 

aesthetascs, and in the proliferation zone, where olfactory receptor 

neurons and associated cells are born, and highest in aesthetascs of the 

senescence zone, which has the oldest olfactory tissue. Csp activity is 

present at approximately the same level in each of the developmental 

zones. Currently we are determining if Csp´s functional activity 

changes due to damage of olfactory tissue. Supported by NIH grant 

DC00312. 


EXOCRINE GLANDS CONTAINING SERINE PROTEASE ARE 

ASSOCIATED WITH OLFACTORY SENSILLA IN THE SPINY 

LOBSTER, PANULIRUS ARGUS 

Derby C.D. 1, Schmidt M. 1 1Biology, Georgia State University, Atlanta, 

GA 

In decapod crustaceans, the olfactory organ is constituted by 

specialized setae - aesthetascs - located on the lateral flagella of the 1st 

antennae. In an attempt to identify molecular components of the 

aesthetascs, diverse genes have been cloned from the lateral flagella of 

the spiny lobster, Panulirus argus, among them a gene encoding a 

CUB-serine protease (Csp) (Levine et al., J. Neurobiol. 49:277-302, 

2001). We found that an antibody against Csp specifically labels cells 

that are closely associated with but not a component of the aesthetascs. 

These cells are arranged in a rosette-like pattern of 5-7 cells around a 

duct with a terminal swelling revealed by labeling with phalloidin, an 

actin marker. The arrangement and phalloidin-reactivity are typical for 

“rosette glands”, an exocrine epithelial gland of decapods (Talbot et al., 

Zoomorphology, 110:329-338, 1991). SEM imaging revealed that in 

Panulirus argus the gland openings are a field of 50-70 dome-shaped 

cuticular structures (ca. 1 µm in diameter) with crescent-shaped pores 

proximal to each row of aesthetascs. Similar small pores have been 

found at the base of aesthetascs of other decapod crustaceans, 

suggesting that the association of exocrine rosette glands with 

aesthetascs is a common feature. From the presence of Csp among the 

excreted substances, we hypothesize that the rosette glands protect the 

aesthetascs from microbial fouling. Supported by NSF IBN-0077474 

and NIH DC00312 

103 


FUNCTIONAL STUDIES OF A SERINE PROTEASE AND AN 

AMINE MONO-OXYGENASE SPECIFIC TO THE LOBSTER 

OLFACTORY ORGAN. 

Stepanyan R. 1, Day K.M. 1, Stepanyan T.D. 2, Mcclintock T.S. 1 

1Physiology, University of Kentucky, Lexington, KY; 2Molecular and 

Biomedical Pharmacology, University of Kentucky, Lexington, KY 

Olfactory specific proteins probably participate in critical functions 

of the olfactory system. We previously identified olfactory enriched 

transcript-03 (OET-03), which is expressed only by collar cells 

associated with the inner dendrites of the olfactory sensory neurons of 

Homarus americanus (Hollins et al., 2003. J. Comp. Neurol. 455:125). 

We now report the complete cDNA sequence of OET-03, a serine 

protease. Confirmation that OET-03 is a protease was obtained by 

assaying protease substrates and inhibitors. Removal of the presumed 

catalytic domain eliminated activity. Preliminary evidence indicates 

that OET-03 is functionally related to the chymotrypsin family. In 

addition, full-length OET-03 specifically reduces proliferation of 

transfected HEK293 cells. We also report the complete sequence of 

OET-02, expressed only by outer auxiliary cells ensheathing the 

proximal regions of the inner dendrites of the sensory neurons. OET-02 

has a unique double mono-oxygenase structure in which the two 

domains characteristic of dopamine beta-hydroxylases are repeated. 

Preliminary assays of olfactory tissue have not identified a biogenic 

amine product of this enzyme, so tests with recombinant OET-02 are 

planned. An antiserum raised against OET-02 confirms the large size of 

this protein (155 kDa) and its restricted expression to the outer auxiliary 

cells. 

Supported by R01 DC02366. 

391 Poster [ ] Olfactory Bulb: Neurophysiology 

QUANTIFICATION OF TAURINE-SYNTHESIZING ENZYME 

MRNA IN OLFACTORY STRUCTURES WITH REAL-TIME 

RT-PCR 

Kratskin I. 1, Hao Y. 1 1Smell and Taste Center, University of 


The olfactory epithelium (OE) and olfactory bulb (OB) are rich in the 

amino acid taurine, which is synthesized in liver and nervous tissue via 

the enzyme cysteine sulfinate decarboxylase (CSD). Our previous 

studies have shown that (i) taurine, acting on GABA receptors, inhibits 

mitral/tufted cells and their synaptic responses to olfactory nerve input, 

(ii) immunoreactivities for taurine and CSD are located in olfactory 

receptor cells and most OB neurons, and (iii) CSD mRNA is expressed 

in the OE and OB. In the present study, gene expression of CSD in the 

rat OE and OB was assessed quantitatively using the real time reverse 

transcription-polymerase chain reaction (RT-PCR) in the LightCycler. 

With this method, a PCR product is detected after each amplification 

cycle by measuring fluorescence emission of a reporter dye, whose 

release is proportional to the amount of the product. A calibration curve 

(a regression line with a correlation coefficient of 0.99) showing the 

relationship between a starting copy number of CSD mRNA and a 

threshold cycle number within a range of 200 to 20000,000 mRNA 

copies was obtained first. Values of the threshold cycle number for 

tissue samples were then detected and a copy number of CSD mRNA 

was calculated using a regression equation. The level of CSD mRNA in 

both OE and OB was about 1000,000 copies/mg tissue. A higher 

amount of about 100,000,000 CSD mRNA copies/mg tissue was 

detected in the liver. The results confirm that CSD mRNA is expressed 

in the OE and OB and provide its quantitative evaluation. (Supported 

by NIDCD grant DC04083).


KV1.3-NULL MUTATION ALTERS SCAFFOLDING 

PROTEINS, OLFACTORY BULB BIOPHYSICS, AND 

GLOMERULI SIZE/ABUNDANCE. 

Perkins R.M. 1, Tucker K. 2, Meredith M. 2, Fadool D. 2 1Dept. of 

Biological Science, Florida State University, Tallahassee, FL; 2Prog. in 

Neurosci. & Mol. Biophys., Florida State University, Tallahassee, FL 

Previously we demonstrated that Kv1.3-null (KO) mice had smaller 

sized and more abundant glomeruli independent of coronal position in 

the olfactory bulb (OB). To test whether projections to the OB were 

altered, we generated Kv1.3-/- mice with a targeted P2-IRES-taulacZ 

mutation (KvP2). Coronal cryosections (12 µm) and whole mounts of 

OB and olfactory epithelium of KvP2 and P2 mice (n=3-5) were 

photographed using a Zeiss Axiocam digital camera with Axiovision 

software. The location of P2 receptors along the olfactory epithelium 

and known P2 glomeruli in the OB showed no noticeable differences 

between P2 and KvP2 mice. In spite of a demonstrated lack of change 

in axonal connectivity, action potentials recorded from mitral cells of 

KO mice exhibited increased hyperpolarization, 10-90% rise time, and 

width at ½ maximum amplitude. Current injection elicited higher 

spiking frequency with less variance in interpulse interval. OB neurons 

are no longer modulated by activation of receptor tyrosine kinases 

(insulin or TrkB receptor) typically associated with the Kv1.3 channel. 

SDS-PAGE indicates the upregulation of Ca2+ channels, two tyr 

kinases, and six adapter proteins in the OB of KO mice. The electrical 

properties in mitral cells from Kv1.3 KO mice could produce rapid 

synchronous firing to strengthen connections to the more numerous 

glomeruli. This interpretation would be consistent with other 

experiments in our laboratory that indicate an increased olfactory ability 

in the mice. Support: NIH DC03387 (NIDCD) & Florida Foundation. 


MULTIPLE ROLES OF TRKB RECEPTOR IN MODULATING 

KV1.3 ION CHANNEL IN THE OLFACTORY BULB. 

Colley B.S. 1, Visegrady A. 1, Fadool D. 1 1Prog. in Neurosci. & Mol. 

Biophysics, Florida State University, Tallahassee, FL 

Previously we have shown that olfactory bulb neuron (OBN) current 

properties are modulated by activation of the neurotrophin receptor 

TrkB, by brain-derived neurotrophic factor (BDNF), to increase 

tyrosine phosphorylation of the potassium channel Kv1.3. Here we 

made Y to F mutations in the Kv1.3 channel to test whether removal of 

the Y phosphorylation motif disrupted BDNF-induced current 

suppression in Kv1.3 + TrkB transfected HEK293 cells. Tyrosines in 

the N and C termini (111-113, 137, 449) were found to be the molecular 

targets for current modulation via phosphorylation as demonstrated by 

patch-clamp electrophysiology and phosphorylation assays using 

various mutant channel constructs compared with the wildtype channel. 

Unexpectedly, we found a 2.1 fold increase in channel protein 

expression (n=4) and a 2 fold increase in peak current amplitude in 

HEK293 cells co-transfected with channel + TrkB versus channel 

alone. This phosphorylation-independent upregulation of Kv1.3 was 

not observed using a GFP-tagged Kv1.3 that likely disrupts an Nterminal 

ER retention motif. Kv1.3 can be immunoprecipitated with 

TrkB in the presence of the adaptor protein nShc and the described 

upregulation is disrupted by substituting trkB K538N or Y490F, which 

are trkB mutants that lack kinase activity or association with nShc 

adaptor respectively. These results suggest that TrkB receptor may 

alter the excitability of OBNs by both phosphorylation-dependent and - 

independent mechanisms involving Kv1.3 ion channel. 

Supported by NIH R01 DC03387 (NIDCD). 

104 


GABAERGIC PERIGLOMERULAR CELLS 

PRESYNAPTICALLY INHIBIT ON INPUT TO THEMSELVES 

Shao Z. 1, Szabo G. 2, Puche A.C. 1, Shipley M.T. 1 1University of 

Maryland at Baltimore, Baltimore, MD; 2Dept. of Gene Tech. and Dev. 

Neurobiol., Institute of Exp. Med., Budapest, ., Hungary 

Olfactory nerve axons terminate in olfactory bulb glomeruli and form 

excitatory synapses onto the dendrites of mitral/tufted (M/T) and 

periglomerular (PG) cells. ON terminals express dopamine D2 and 

GABAB receptors and there is evidence that DA and GABA 

presynaptically inhibit the release of glutamate from ON synapses. It is 

thought that ON excitation of GABAergic PG cells releases GABA 

back onto ON terminals, but there is no direct evidence for this. To 

investigate this question we used whole cell patch clamp recordings of 

identified GABAergic PG cells in a line of mice expressing green 

fluorescent protein under the control of the glutamic acid decarboxylase 

65kDa gene (GAD65-GFP). GAD65-GFP+ GABAergic PG cells are 

excited by ON stimulation; 30%-40% receive monosynaptic ON input, 

the remainder have variable latency, polysynaptic responses to ON 

stimulation. For those that receive monosynaptic input, paired-pulse 

ON stimulation caused a reduction of EPSC amplitude in response to 

the second pulse. This paired-pulse inhibition was abolished by addition 

of selective GABAB receptor antagonists. This indicates that ON 

terminals targeting GABAergic PG cells are subject to GABAergic 

presynaptic inhibition. When step-depolarization of the cell was used to 

evoke GABA release prior to stimulation of ON, the magnitude of the 

ON-evoked EPSC was reduced by ~30%. The reduction was prevented 

by application of selective GABAB receptor antagonists. This 

demonstrates that a GABAergic PG cell can presynaptically inhibit the 

ON terminals targeting that same PG cell. GABAergic PG cells, 

therefore, may provide feedback, presynaptic inhibition that limits 

subsequent glutamate release from ON terminals. Supported by NIH 

DC02173, DC00347 & NS36940.


INTRAGLOMERULAR SYNCHRONOUS CALCIUM 

OSCILLATIONS OF PERIGLOMERULAR CELLS IN THE 

MOUSE OLFACTORY BULB 

Jia F. 1, Shepherd G.M. 1, Chen W.R. 1 1Neurobiology, Yale University, 

New Haven, CT 

Synchronous neuronal oscillations have been widely considered to be 

an important mechanism for coding and processing odor information. 

Oscillations of different frequency ranges have been reported in the 

olfactory bulbs of a wide range of vertebrate species. Olfactory sensory 

neurons expressing the same odorant receptor project to a few 

glomeruli in the mammalian olfactory bulb. Thus, glomeruli are key 

for the neural basis of olfactory coding. In this study we have used 

optical imaging methods to map neuronal synchrony among 

periglomerular (PG) cell populations that either share a common 

glomerulus or belong to different glomeruli. An ester form of calciumsensitive 

dye was used to load hundreds of neurons in the olfactory bulb 

slices. Thirty to one hundred fifty seconds of calcium imaging was 

performed to analyze the dynamic structure of PG-cell spontaneous 

activities by a cooled CCD camera. We observed novel slow (


OLFACTORY NERVE-EVOKED METABOTROPIC 

GLUTAMATE RECEPTOR (MGLUR)-MEDIATED 

RESPONSES IN RAT OLFACTORY BULB MITRAL CELLS 

Zhu M. 1, Heinbockel T. 2, Ennis M. 1 1Anatomy and Neurobiology, 

University of Tennessee, Memphis, TN; 2Anatomy and Neurobiology, 

University of Maryland at Baltimore, Baltimore, MD 

The group I mGluR, mGluR1, is highly expressed on mitral cell 

(MC) apical dendrites, and thus may be activated by glutamate from the 

olfactory nerve (ON) and/or mitral/tufted cells. We have shown that 

mGluR1 agonists potently excite MCs. Here we investigated if ON 

stimulation engages mGluR-mediated responses in MCs in rat olfactory 

bulb slices. In voltage clamp recordings, EPSCs evoked by single ON 

shocks were unaffected by the potent, non-selective mGluR antagonist 

LY341495 (50-100 uM). Single ON shocks in the presence of 

ionotropic glutamate and GABAa receptor antagonists (CNQX, APV, 

Gabazine) did not evoke EPSCs, except at high intensities (>600uA). In 

the same cell (in CNQX, APV, Gabazine), brief high frequency ON 

trains (6 pulses at 10-200Hz) induced long duration EPSCs that were 

blocked by TTX or by low calcium ACSF. Application of glutamate 

uptake inhibitor (TBOA 100uM) and a glutamate transporter inhibitor 

(THA 300uM) increased the amplitude and duration of responses to 

single or trains of ON stimuli. These agents also unmasked “latent” 

responses to single ON stimuli in some cells. Additional application 

LY341495 (50-100uM) reduced or completely blocked ON-evoked 

responses observed in the presence CNQX, Gabazine and APV. These 

results demonstrate that ON stimulation evokes frequency dependent 

excitatory responses in MCs that are mediated, in part, by activation of 

mGluRs. Such responses are maximally engaged during high frequency 

ON input, as occurs during odor stimulation. Support: PHS grants 

DC03195, DC00347 


METABOTROPIC GLUTAMATE RECEPTORS (MGLURS) 

ENHANCE SYNAPTIC INTERACTIONS AMONG 

JUXTAGLOMERULAR (JG) NEURONS IN OLFACTORY 

BULB GLOMERULI 

Hayar A. 1, Heinbockel T. 2, Shipley M.T. 2, Ennis M. 1 1Dept. of Anatomy 

and Neurobiology, University of Tennessee, Memphis, TN; 2Dept. of 

Anatomy and Neurobiology, University of Maryland, Baltimore, MD 

mGluRs are present on JG cells and may regulate dendrodendritic 

synapses. We investigated the actions of mGluR agonists in identified 

JG cells in slices. Group I (DHPG), and group II (CCGI) mGluR 

agonists, but not group III mGluR agonists (L-AP4) increased the 

number of spikes/burst in external tufted (ET) cells in the presence of 

synaptic blockers. In the presence of TTX and synaptic blockers, 

DHPG and CCGI directly excite and induce an inward current in ET 

cells. They also increased the frequency of spontaneous and miniature 

IPSCs in ET cells. This effect, abolished by the Ca2+ channel blocker, 

cadmium, may be due to increased ET and/or mitral cell dendritic 

excitability and/or a direct, mGluR-mediated excitatory effect on the 

dendrites of GABAergic periglomerular (PG) cells. DHPG and CCGI 

also increased the frequency of miniature EPSCs in PG and short axon 

(SA) cells but not in ET cells, suggesting that activation of mGluRs on 

ET cell dendrites, increases glutamate release onto PG and SA cells. In 

the presence of fast synaptic blockers and the Na + channel blocker QX- 

314 in the pipette, DHPG induced in ET cells rhythmic events 

associated with membrane current oscillations (~2 Hz) that are possibly 

due to gap junctions among ET cells. mGluR agonists also decreased 

olfactory nerve-evoked EPSCs in ET and mitral cells via a GABA - B 

mediated presynaptic mechanism. Thus, mGluR agonists directly 

activate rhythmically bursting ET cells and enhance glomerular 

dendrodendritic interactions. Support: PHS Grants: DC03195, 

DC05676. 

106 


IN VIVO MOUSE PREPARATION FOR OLFACTORY BULB 

ELECTROPHYSIOLOGY 

Mast T. 1, Griff E. 2 1Biological Sciences, University of Cincinnati*, 

Cincinnati, OH; 2Biological Sciences, University of Cincinnati, 

Cincinnati, OH 

The objective of this study was to develop an in vivo mouse 

preparation for recording from the main olfactory bulb (MOB). An aim 

was to establish a protocol using an injectable anesthetic such as chloral 

hydrate. The anesthetic plane was evaluated using the EEG and the 

hindpaw withdrawal response. Single-unit recordings measured the 

spontaneous activity of neurons in the MOB. The amount of chloral 

hydrate required to maintain a surgical plane of anesthesia was linearly 

correlated with a decrease in MOB spontaneous activity (p=0.2; n=13), 

and could be lethal. Therefore, analgesic supplements to chloral 

hydrate anesthesia were investigated. Supplementation with 

buprenorphine, a synthetic µ-opioid receptor agonist, was problematic. 

Buprenorphine at doses of 0.02, 0.05, and 0.2 mg/kg reduced 

spontaneous activity of bulbar neurons by 19, 45, and 54%, 

respectively. In contrast, ketoprofen, a non-steroidal anti-inflammatory 

with reported analgesic activity, did not inhibit spontaneous activity at 

doses of 100 or 200 mg/kg. Importantly, mice given 100 mg/kg 

ketoprofen at the beginning of an experiment, before surgery, required 

significantly less chloral hydrate than control animals (p=0.05; n=18). 

Animals in both groups were maintained at a surgical plane of 

anesthesia. Lastly, administration of ketoprofen during an experiment 

changed the EEG indicative of a deeper plane of anesthesia. Thus, 

chloral hydrate supplemented with ketoprofen in the mouse provides an 

in vivo preparation for stable, long-term recording of neurons in the 

MOB. This work was supported in part by NIH grant 1R15DC04548 to 

ERG. 


SPONTANEOUS ACTIVITY OF MAIN OLFACTORY BULB 

NEURONS IN THE RAT 

Griff E.R. 1, Stakic J. 2, Suchanek J. 2 1Biological Sciences, University of 

Cincinnati*, Cincinnti, OH; 2Biological Sciences, University of 


Neurons in the main olfactory bulb (MOB) are spontaneously active, 

with rates above 30 Hz reported. In this study, the sources of this 

activity were investigated. We specifically tested the hypothesis that 

the spontaneous activity of bulbar neurons is at least partly due to 

spontaneous activity in olfactory receptor neurons (ORNs). 

This study was conducted using anesthetized rats breathing clean air. 

The conduction of ORN action potentials was blocked by cooling the 

olfactory nerve rostral to the cribiform plate. To assess the efficacy of 

the cold block, a bipolar stimulation electrode was positioned rostral to 

the cold probe, and field potentials were recorded from the MOB while 

cooling the nerve. Cooling completely and reversibly abolished the 

field potentials. The spontaneous activity of single units was recorded 

from the same region of the MOB, and the recording sites subsequently 

marked with dye. Mitral and tufted cells were further identified by 

antidromic activation from the lateral olfactory tract. To date, for every 

cell recorded that exhibited spontaneous activity (from glomerular, 

external plexiform, and mitral cell layers of the MOB), cold decreased 

this activity. This study suggests that ORNs are spontaneously active in 

the rat. Thus, in the absence of odor stimulation, ORN spontaneous 

activity, directly and/or via bulbar circuits, at least in part sets and 

maintains neuronal activity in the MOB. 

This work was supported in part by NIH grant 1R15DC04548 to 

ERG.


MULTIUNIT AND FIELD POTENTIAL RECORDINGS IN RAT 

OLFACTORY BULB 

Sherrill L. 1, Green E. 1, Scott J.W. 1 1Cell Biology, Emory University, 

Atlanta, GA 

To test the relationship between olfactory bulb slow waves and single 

cell responses, we conducted recordings with silicon based multiple 

electrodes. Field potential recordings are used to calculate one and twodimensional 

current source density in rats anesthetized with urethane 

(1.5 gm/K) or chloral hydrate (0.4/K). Antidromic stimulation of the 

lateral olfactory tract is used to localize the mitral cell layer and in some 

cases to identify output cells. Under both anesthetics a number of 

odorants can evoke spike responses and waves in the 30-60 Hz range at 

concentrations in the range of 10-3 times saturated vapor in our 

preliminary results. The field responses evoked by odorants are more 

obvious in the voltage records than in the current density calculations. 

This agrees with our findings that the voltage oscillations are not well 

localized in the olfactory bulb. We failed to find spikes in either the 

mitral or granule layers that are strongly synchronized with slow waves. 

On the other hand it has been common to see strong inhibition or 

excitation of spikes in the mitral cell layer during bursts of oscillations. 

While some of these cells may be too strongly inhibited to show 

oscillations, preliminary attempts to uncover the underlying oscillation 

by reducing odorant concentration have been unsuccessful. While the 

prominence of these oscillatory phenomenia in the bulb suggests that 

they represent a strong synchronization of inibitory interneurons, our 

results suggest that it will be difficult to show simple relationships with 

spike activity. Supported by NIH grant DC00113. Multichannel silicon 

probes were provided by the Univ.Mich. Center for Neural 

Communication Technology sponsored by NIH NIBIB grant P41- 

RR09754. 


NITRIC OXIDE MODULATES ANTENNAL LOBE NEURON 

ACTIVITY IN THE MOTH, MANDUCA SEXTA, THROUGH 

SOLUBLE GUANYLYL CYCLASE-DEPENDENT 

MECHANISMS 

Wilson C. 1, Christensen T. 1, Nighorn A. 1 1Neurobiology, University of 

Arizona, Tucson, AZ 

Gaseous messengers like nitric oxide (NO) have been implicated in a 

number of physiological processes including the modulation of 

olfactory representations in the brain. NO and its signaling components 

have been studied in the olfactory systems of several species, but the 

function of NO in olfactory processing remains elusive. In the moth, 

Manduca sexta, NO synthase (NOS) was found in olfactory receptor 

neurons (ORNs), while a well-characterized target of NO, soluble 

guanylyl cyclase (sGC) was found in the post-synaptic targets of ORNs 

in antennal lobe (AL). This expression pattern, along with preliminary 

imaging data showing increases in fluorescence of an NO-sensitive dye 

in odor-activated glomeruli, led to a hypothesis that NO is released 

focally when odor is present, and then modulates signaling in the 

activated glomeruli by acting on the sGC-containing neurons in the AL. 

This hypothesis was tested with multi-channel and intracellular 

recording methods coupled with pharmacological manipulation of NO 

levels and the activity of sGC in the AL. Blocking NO production with 

L-NAME resulted in an overall decrease of spontaneous activity in AL 

neurons, and this effect was mimicked reversibly by the sGC inhibitor 

ODQ. Odor-evoked responses were also diminished when NOdependent 

signaling was blocked. These results suggest that NO is an 

important modulator of odor responsiveness, and that sGC-dependent 

signaling is at least partially responsible for the observed changes in 

glomerular activity levels. Supported by NIH-NIDCD DC04292 and 

DC06368. 

107 

404 Poster [ ] Multimodal Integration 

BEHAVIORAL RESPONSES OF THE CRAYFISH 

PROCAMBARUS CLARKII TO SINGLE COMPOUNDS 

Corotto F.S. 1, Johnston M.E. 1, Rogers J.L. 1, Williams J.M. 1 

1Department of Biology, North Georgia College & State University, 

Dahlonega, GA 

We investigated chemosensory behavior of the crayfish Procambarus 

clarkii in response to glutamate and glucose (not stimulatory to leg 

chemoreceptors in physiological tests; J. Chem. Ecol., 28:1117-1130), 

ammonium, glycine, maltose, and trehalose (physiological stimuli of 

varying efficacies), and a blank. Each animal was acclimated to a 1.5 L 

testing chamber for >2 h and was stationary in the chamber´s shelter 

when tested. Individual compounds were injected in 10 mL aliquots 

into a 149 mL/min carrier flow and were diluted to 200 µM-2 mM 

within the testing chamber according to conductivity measurements. 

Each animal was tested once. Responses were filmed, and the time 

spent probing with pereopods, the time spent exploring, and the number 

of dactyl clasps were quantified by observers blind to the stimulus. 

ANOVA followed by Fisher´s PLSD tests indicated the following 

elicited responses that differed significantly from that evoked by the 

blank: glucose for the time spent probing; glucose, maltose, and glycine 

for exploration time; glucose, maltose, and trehalose for the number of 

dactyl clasps. Ammonium´s ineffectiveness parallels its weakness as a 

physiological stimulus. Trehalose was the most potent physiological 

stimulus tested, but it was no more effective in evoking behavioral 

responses than glucose or maltose. Glucose was a potent behavioral 

stimulus, but earlier physiological tests failed to show responses to 

glucose from leg chemoreceptor cells. Either receptor cells for glucose 

are elsewhere or they are on the legs in small numbers and carry a 

disproportionate influence on behavior. 


DUAL INTRACELLULAR RECORDINGS FROM SINGLE 

PARASOL CELLS REVEAL IMPULSE BURST INITIATION 

SITE AND DENDRITIC TRAJECTORIES 

Mellon D. 1 1Biology, University of Virginia, Charlottesville, VA 

Parasol cells are multimodal sensory interneurons in the crustacean 

forebrain. They exhibit complex and interesting forms of electrical 

activity, investigations of which may reveal novel concepts of dendritic 

integrative mechanisms. We are using dual intracellular recordings 

from individual parasol cells to examine impulse and impulse burst 

initiation sites and propagation within the dendritic tree. Previous 

findings (Mellon, DeF., J. Neurophysiol. 90:2465 [2003]) indicated that 

impulses are initiated at a low threshold region on the dendritic trunk 

adjacent to the basal branch points. Dual simultaneous recordings from 

different basal branches of the same neuron support this interpretation 

and, furthermore, suggest that impulse bursts arise at a trunk region 

distant from (more ventral to) the intitation zone of single spikes. 

Orthodromic stimulation via the olfactory-globular tract or antidromic 

stimulation via the parasol cell axon terminals generates slightly 

different impulse latencies in simultaneous recordings from basal 

branches on opposite sides of the dendritic tree. Impulse bursts, evoked 

either by photic stimulation of the compound eyes or by posthyperpolarization-activated 

I h , invade both recording sites and exhibit 

latency differences identical with those of individual spikes following 

orthodromic or antidromic stimulation. These findings support 

conclusions regarding a trunk site for impulse initiation and provide 

evidence for bursts also being initiated on the dendritic trunk. 

Supported by NSF.


TUNING OF MECHANORECEPTORS IN THE LOBSTER 

ANTENNULE 

Miller-Sims V. 1, Atema J. 1 1Biology, Boston University, Woods Hole, 

MA 

The American lobster, Homarus americanus, is capable of tracking 

an odor to its source in a turbulent plume. In such a plume an animal 

encounters hydrodynamic and chemical signals. Concurrent reception 

of odor and flow could be an important cue for odor plume tracking. 

The lateral antennule contains many chemoreceptor neurons and is 

important for successful tracking. We now want to determine the 

bandwidth in which the lobster uses lateral antennule mechanoreceptors 

to monitor the hydrodynamic properties of the plume. Under oscillatory 

flow conditions the antennule has a resonance of frequency of 5-12 Hz; 

antennular mechanoreceptors could also be expected to respond 

optimally in this range. In this experiment frequency synchronization is 

used to determine the types of hydrodynamic stimuli to which the 

antennule is capable of responding. The distal end of the antennule was 

fixed in a speaker driven oscillatory flow chamber to stimulate whole 

antennule movement. We recorded extracellular responses from 

antennular axons to oscillatory antennule movement over a frequency 

range of 1-128 Hz in an amplitude range of 16 to125 µm. Responses 

were recorded from 30 cells and synchronization coefficients were 

computed for each stimulus presentation. As a population these cells 

were capable of synchronizing to the stimulus at frequencies between 4 

and 64 Hz. Cells with low to no background spiking synchronized best 

at lower frequencies of 4-16 Hz while cells with high background 

spiking synchronized best at higher frequencies between 16 and 64 Hz. 

This frequency range may have significance in monitoring turbulent 

plume dynamics. Funding Source: NSF IBN-0091358 


OCTOPAMINE-IMMUNOREACTIVE NEURONS IN THE 

OLFACTORY AND GUSTATORY CENTERS IN THE BRAIN 

OF MANDUCA SEXTA. 

Dacks A. 1, Christensen T. 1, Hildebrand J.G. 2 1Neurobiology, University 

of Arizona, Tucson, AZ; 2Univeristy of Arizona*, Tucson, AZ 

Octopamine (OA) is a neuroactive monoamine that is found in the 

nervous systems of many invertebrates and plays a key role in different 

aspects of behavior, including associative learning. In this study, we 

used a monoclonal antibody against OA (gift of H.-J. Agricola) to 

examine the distribution of OA-immunoreactive (OA-ir) cells in the 

olfactory and gustatory neuropil centers that mediate olfactory 

conditioning in the hawkmoth Manduca sexta. OA-ir processes were 

observed in many regions of the brain with the distinct exception of the 

upper division of the central body. We found 11 ventral unpaired 

median (VUM) cell bodies in the subesophageal ganglion that express 

OA-ir. Two particularly elaborate cells project bilaterally: one 

interconnects the antennal lobes and the calyces (input region) of the 

mushroom bodies, and a second cell innervates the gamma-lobe of the 

mushroom bodies. The branching patterns of Manduca VUM neurons 

are therefore similar, but not identical to those in other insects, 

including the uniquely identifiable VUMmx1 neuron in the honeybee. 

Supported by grants from NIH/NIDCD and NSERC Canada. 

108 


TEMPORAL INTERACTION OF OLFACTORY AND 

TRIGEMINAL PROCESSING 

Heilmann S.K. 1, Hummel T. 1 1Otorhinolaryngology, University of 

Dresden Medical School, Dresden, Germany 

Aim: 

In everyday life, olfactory and trigeminal sensations hardly ever 

occur seperately. Contrary, most odors in our environment will elicit 

excitation of both olfactory receptor cells and trigeminal neurons. 

However, the temporal resolution of this interaction has not been 

studied in detail yet, mostly due to technical difficulties. Aim of this 

study was to analyse the interaction of both systems using intensity 

estimates following olfactory and trigeminal stimuli with different 

interstimulus intervals. 

Methods: 

Participants were 11 women and 12 men (age 21-29 years). 

Trigeminal (50 % v/v CO2) and olfactory (5 ppm H2S) stimuli were 

presented at different interstimulus intervals (0, 700, 1200, 2200, 4200 

and 8200 ms). One group of subjects received first the olfactory 

stimulus, followed by a trigeminal stimulation (OT). A second group 

received the stimuli in reversed order (TO). Intensity estimates were 

recorded using a visual analogue scale. 

Results: 

OT: Olfactory stimulation resulted in a significant enhancement of 

perceived intensity of the following trigeminal stimulus for up to 1000 

ms. When the stimulation sequence was reversed (TO), perceived 

intensity of the olfactory stimulus was significantly reduced for up to 

2000 ms. 

Summary: 

With regard to the present experimental conditions, the olfactory and 

trigeminal systems interact within a time frame of 1-2 s. It appears that 

trigeminal activation affects the processing of other chemosensory 

stimuli for a longer period than olfactory excitation. 


PROP TASTER STATUS VERSUS TEXTURE AND FLAVOR 

SENSATIONS FOR LOW-FAT SEMI-SOLID FOODS 

De Wijk R.A. 1, Weenen H. 2 1Wageningen Center for Food 

Sciences/A&F, Wageningen, Netherlands; 2WCFS/TNO-V, 

Wageningen, Netherlands 

The hypothesis was tested that sensitivity to 6-n-propylthiouracil 

(PROP) was related to texture and flavor perception, and preference for 

16 commercial vanilla custard desserts (mostly starch-based, fat levels 

between 0.1% and 4%). A group of 175 naive consumers rated the 

intensity of a PROP stimulus presented on a filter paper using a gLMS. 

The group was divided into 25% non-tasters (NT, rating=86%). PROP status affected ratings for creaminess, fattiness, 

thickness, melting, heterogeneity, airiness, stickiness, and roughness, 

and preference significantly (p


EFFECTS OF GINKGO BILOBA ON CHEMOSENSORY 

FUNCTION 

Mattes R.D. 1, Pawlik K. 2 1Foods and Nutrition, Purdue University, 

West Lafayette, IN; 2Foods and Nutrition, Purdue University, W. 

Lafayette, IN 

Diminutions and losses of chemosensory function are common. 

While diagnostic procedures have advanced markedly, there are few 

known methods to enhance chemosensory function. Ginko biloba 

reportedly enhances cerebral blood flow, neurogenesis in the olfactory 

epithelium, neurotransmission and cognition. Improved odor 

recognition has been noted in rats administered the extract. This trial 

examined the effects of acute and chronic extract administration on 

taste and smell threshold sensitivity and odor recognition in healthy 

humans. A randomized, double-blind, placebo-controlled trial was 

underetaken with 30 individuals meeting strict eligibility criteria 

including non-use of medications, nutraceuticals or supplements that 

can affect sensory function. Active treatment consisted of a daily 

0.87mg/kg dose (2.35% Ginkgo biloba extract standardized to 24% 

flavanoids and 6% terpenes (%w/w)) administed TID for 13 weeks. 

Forced-choice, staircase thresholds for sucrose, NaCl and butanol and 

odor identification were measured at weeks 0, 1, 5, 9 and 13 following 

a standardized meal. No significant treatment or treatment X time 

interactions were observed for the olfactory indices. Taste thresholds 

were significantly higher with active treatment over the trial. This trial 

revealed no beneficial effects of Ginkgo biloba on taste or smell in 

healthy adults. Whether benefits may be realized by individuals with 

diminished chemosensory function is not known. 

Supported by: Purdue-UAB Botanicals Center for Dietary 

Supplement Research #P50 AT-00477. 


INFLUENCES OF ANTIHYPERTENSIVE AND 

ANTIHYPERLIPIDEMIC DRUGS ON THE SENSES OF TASTE 

AND SMELL: AN OVERVIEW 

Kerr K.L. 1, Philip S. 1, Reddy K. 1, Doty R.L. 1 1Smell and Taste Center, 

Department of Otorhinolaryngology, University of Pennsylvania 

Medical Center, Philadelphia, PA 

According to the Physician´s Desk Reference (PDR), 36% of modern 

antihypertensive and antihyperlipidemic drugs produce untoward 

alterations in chemosensory perception. Such disturbances can 

adversely affect the quality of life, produce noncompliance to 

medication schedules, and may result in decreased food intake, loss of 

appetite, weight decrement, and depression. This abstract lists the 

primary antihypertensive and antihyperlipidemic drugs that adversely 

alter chemosensory function. Among these, angiotensin-converting 

enzyme (ACE) inhibitors and antihyperlipidemic drugs are the worst 

offenders, as seven of the 10 (70%) ACE inhibitors and seven of the 10 

(70%) antihyperlipidemic drugs included in the PDR are listed as 

having chemosensory side effects. Of the 15 calcium-channel blockers 

in the PDR, eight (53%) have been reported to induce taste or smell 

disturbances. Moreover, chemosensory dysfunctions have also been 

reported with use of angiotensin II antagonists and diuretics. This 

abstract also provides information on better defining the nature of the 

dysfunction, outlines testing strategies and available tests that could be 

used to better define the prevalence of the dysfunction, and summarizes 

means for mitigating such alterations. 

This abstract was supported, in part, by Grants PO1 DC 00161, RO1 

DC 04278, RO1 DC 02974, and RO1 AG27496 (RLD) 

109 


REPEATABILITY AND INTERCORRELATIONS OF SENSORY 

AND COGNITIVE TESTS IN UNMEDICATED ELDERLY 

SUBJECTS 

Schiffman S.S. 1, Murray S.G. 1, Watson E.L. 1 1Psychiatry, Duke 

University, Durham, NC 

The purpose of the study was threefold: 1) to determine if age-related 

losses in various sensory functions are correlated, 2) to determine if 

sensory acuity is related to cognitive performance, and 3) to determine 

if practice effects occur with repeated testing over a 6 month period. 

Elderly individuals between 65 and 85 years of age in good health on 

no medications (other than hormone replacement) were tested on the 

same battery of cognitive and sensory tests measuring taste, smell, 

vision, hearing, and touch. There were a total of 71 subjects (29 male, 

42 female) with a mean age of 72.6 years and mean years of education 

of 16 years. Subjects were tested at the following time points: baseline, 

at 3 weeks, at 2 months, and at 6 months. Data for each time point were 

collected during two 2-hour sessions performed within 1 week of each 

other. The results over the four sessions show considerable variability. 

Data analysis indicates rather low correlations between tests of each 

sensory modality and with cognition. Repeated testing of elderly 

subjects over the 6 month period showed the following trends: 1) selfrated 

perception of taste and smell ability decreased, 2) cognitive 

performance improved slightly, and 3) olfactory identification and odor 

memory scores decreased slightly. These findings suggest that repeated 

testing is necessary to evaluate accurately some sensory and cognitive 

functions in the elderly. Supported by a grant from National Institute on 

Aging NIA AG 00443. 


HEDONIC CONTRAST AND HEDONIC DISCRIMINATION 

Allen D. 1, Henley M. 1, Zellner D. 1, Parker S. 2 1Psychology, Montclair 

State University, Upper Montclair, NJ; 2Psychology, American 

University, Washington, DC 

Stimuli are rated as less intense when compared to very intense 

context stimuli than when presented alone or with less intense context 

stimuli (Frederiksen, 1975), a phenomenon called contrast. In audition, 

loud contextual sounds engender a reduction in intensity discrimination, 

perhaps by changing the psychophysical loudness function (Parker et 

al., 2002). We recently demonstrated contrast with hedonic judgments 

(Zellner et al., 2003). Here we look for a reduced hedonic 

discrimination accompanying hedonic contrast. 

In Experiment 1 two groups of subjects rated the pleasantness of 

two diluted fruit drinks (Test drinks). Group 1 drank and rated the Test 

drinks. Group 2 rated four other full-strength fruit drinks (Context 

drinks) before the Test drinks. Group 2 rated the Test drinks as less 

pleasant (M=-22.22) than did Group 1 (M=+8.44), t(32)=2.63, p=.013. 

Thus, hedonic contrast occurred. 

Experiment 2 investigated whether reduced hedonic discrimination 

accompanies that hedonic contrast. Subjects rated how much more they 

liked the preferred Test drink than the other one. On the10-point rating 

scale, 1 meant “slightly more” and 10 meant “very much more”. Group 

1 drank only the diluted Test drinks and rated their difference in 

likeability. Group 2 drank and rated them after exposure to the four fullstrength 

Context drinks. Group 2 rated the two Test drinks as 

hedonically less different (M=1.31) than did Group 1 (M=3.63), 

t(30)=2.69, p=.012. 

These results demonstrate reduced hedonic discrimination 

accompanying hedonic contrast, paralleling phenomena seen in studies 

of loudness. Perhaps the psychophysical growth of pleasantness is 

malleable.


MEMANTINE AND MECAMYLAMINE ALTER NICOTINE 

PERCEPTION IN MAN 

Thuerauf N. 1, Lunkenheimer B. 1, Lunkenheimer J. 1, Bleich S. 1, 

Schlabeck M. 1, Kornhuber J. 1 1Department of Psychiatry and 

Psychotherapy, University of Erlangen-Nürnberg, Erlangen, Germany 

NMDA-receptors are present at different regions of the olfactory 

system and NMDA-knockout mice were profoundly impaired in 

olfactory discrimination. Memantine, a non-competitive, selective 

NMDA-antagonist with a voltage-dependent, fast unblocking kinetic 

can be used in man. Neuronal nicotinic Acetylcholine receptors 

(nAchRs) are present at the nasal mucosa. Mecamylamine, an 

Acetylcholine-receptor-antagonist, blocked painful responses to 

nicotine following chemical stimulation of the tongue. In the present 

study we investigated (1) the influence of Memantine (oral application) 

and of (2) Mecamylamine (local application) on nicotine perception 

using a placebo controlled double blind (1) parallel group and (2) a 

two-fold crossover design. Nicotine perception was studied under 

Memantine / placebo (steady state condition, n=15) and under 

Mecamaylamine / placebo (following local application, n=15) 

following chemical stimulation of the nasal cavity with olfactory and 

trigeminal stimulus concentrations. Memantine significantly reduced 

the olfactory intensity estimates of S(-)-nicotine and Mecamylamine 

significantly reduced trigeminal intensity estimates of nicotine 

enantiomers. Thus, Acetylcholine-receptor- and NMDA-antagonists are 

effective tools to influence nicotine perception in man acting with 

different specificity. 

Acknowledgement: Research described in this article was supported 

by Philip Morris USA Inc. (Philip Morris External Research Program / 

Postdoctoral Fellowship). 


MULTIPLE SHORT-TERM EFFECTS OF ENVIRONMENTAL 

TOBACCO SMOKE AND PROPIONIC ACID 

Suarez J.C. 1, Whitt R. 1, Walker D. 1, Walker J. 1 1Sensory Research 

Institute, Florida State University, Tallahassee, FL 

As part of a research program to better understand short-term 

responses of humans to environmental chemical exposures, we are 

measuring multiple responses/impacts from 20 normal (no evidence of 

chemosensory deficits or of chemical hypersensitivity) participants (Ps) 

in a previously described (ACHEMS 2003) 10-m3 environmental 

chamber. Ps are tested in pairs and are given one 100-minute test 

session with each of eight stimulus conditions. By varying the 

proportion of total chamber flow (fixed at 1000 LPM) derived from an 

antechamber in which one or two smokers puff in response to signal 

lights, we approximate three target concentrations of environmental 

tobacco smoke (ETS): 15, 100 and 800 mg/m3 of ETS-attributable 

respirable suspended particulate. As a control, smokers puff on unlit 

cigarettes. Four concentrations (0, 1, 10, 15 ppm) of propionic acid 

(PA) are generated by varying the proportion of chamber flow passed 

over liquid PA held in glass saturators. Except with 15 ppm PA (where 

the plateau is held for minutes 20-30), concentrations of PA and ETS 

rise during minutes 11-20 and then are held through minute 70, when an 

exponential decline begins. Sensory/symptom, breathing, eyeblink rate, 

psychological state and information processing speed responses/impacts 

are measured at various times over the course of the session. As a first 

step toward an improved understanding of the effects of various 

environmental contaminants on short-term responses in humans, our 

analyses evaluate stimulus type, concentration and time as determinants 

of the magnitude of the change in each endpoint. 

Research supported in part by Philip Morris USA Inc. 

110 

416 Poster [ ] Taste: Umami 

COMPARISON OF THE TASTES OF MSG AND L-ALANINE 

Taylor-Burds C.C. 1, Westburg A.M. 1, Wifall T.C. 1, Delay E.R. 1 

1Neuroscience Program, Regis University, Denver, CO 

Monosodium Glutamate (MSG) is an amino acid that occurs 

naturally in protein rich foods such as meat and dairy products. 

Chaurdhari et al. (1996) showed that MSG activates taste-mGluR4 

receptors. Nelson et al. (2002) found that the receptor T1R1/T1R3 

responds to many amino acids including MSG, but not to stimuli 

perceptually sweet to humans. Alternatively, the T1R2/T1R3 receptor 

responds to sugars and artificial sweeteners but not to umami 

substances. Nevertheless, conditioned taste aversion (CTA) studies 

report that rats perceive similarities in taste between MSG and several 

sweet substances when the sodium taste is reduced by amiloride, a 

sodium channel blocker (Heyer et al., 2003). Several L-amino acids, 

such as L-alanine (ALA), elicit a variety of taste qualities including 

“sweet” in humans (Schiffman et al, 1981). Two questions were 

addressed in this study: Do ALA and MSG share taste qualities, and if 

so can rats distinguish between the two substances? CTA experiments 

were done with water-deprived rats conditioned to either ALA or MSG, 

and then tested against 3 concentrations of the opposite stimulus, the 

conditioned stimulus, and control substances. The results revealed a 

strong perceptual similarity between MSG and ALA. To assess the 

strength of similarities in these tastes, discrimination experiments were 

also conducted. Rats can discriminate between the two substances but 

the discrimination is significantly difficult when amiloride or amiloride 

+ NaCl is added to control for the taste of Na+ in MSG. These results 

suggest that MSG and ALA may share similar but not identical afferent 

signaling. 


L-SERINE, GLYCINE, AND MSG TASTES IN RATS: 

GENERALIZATION OF CONDITIONED TASTE AVERSION 

Mitzelfelt J.D. 1, Westburg A.M. 1, Delay E.R. 1 1Neuroscience Program, 

Regis University, Denver, CO 

Recent molecular studies suggest that L-amino acids and substances 

that elicit an “umami” taste may be detected by T1R1/T1R3 

heterodimeric receptors in taste receptor cells whereas “sweet” 

substances are detected by T1R2/T1R3 receptors. Monosodium 

glutamate (MSG) is a naturally occurring amino acid found in most 

protein rich foods such as meats, dairy products, and some vegetables, 

and is a prototypical substance that elicits an “umami” taste. In humans, 

L-amino acids can elicit quite different tastes (Schiffman et al, 1981). 

However, other than preference measures there is little behavioral 

research on the taste qualities of amino acids in nonhuman mammalian 

species. In this study, conditioned taste aversion (CTA) methods were 

used to see if aversions to L-Serine and Glycine, both common and 

naturally occurring amino acids, would cross-generalize to L-MSG in 

short duration, reactive tests. In contrast to other CTA studies, 

amiloride was present to reduce the taste of the sodium ion. A lithium 

chloride-induced aversion to 100 mM MSG generalized to L-Serine and 

Glycine at concentrations as low as 10 mM when amiloride was present 

in all solutions. Similar generalization to MSG was detected when the 

rats were conditioned with L-Serine and Glycine. These results suggest 

that MSG shares taste qualities with L-Serine and Glycine, possibly 

through common afferent signaling mechanisms. Supported by NIH 

R15DC005962


POLYMORPHISMS OF KNOWN MONOSODIUM 

GLUTAMATE (MSG) TASTE RECEPTORS AND BIMODAL 

DISTRIBUTION OF SENSITIVITY TO GLUTAMATE SAVORY 

TASTE 

Alarcon S.M. 1, Mascioli K.J. 1, Reed D. 1, Keast R. 1, Tharp C. 1, Lui S. 1, 

Ahmed O. 1, Breslin P. 1 1Monell Chemical Senses Center, Philadelphia, 

PA 

Monosodium glutamate (MSG) elicits a unique taste quality, often 

labeled savory, brothy, or umami. This quality is thought to underlie the 

protein and amino acid tastes, which convey a preferred flavor in many 

foods. But a small subset of the population (~6%) is insensitive to this 

taste quality. Subjects were screened for their ability to distinguish 29 

mM NaCl vs 29 mM MSG in a forced-choice triangle test. The few 

subjects who could not discriminate these stimuli also demonstrated an 

insensitivity to glutamate on a concentration-intensity scaling task. 

Furthermore, the synergy of savory taste that occurs for most subjects 

when MSG is mixed with 5' ribonuclotides, such as GMP or IMP, is 

lacking in selected individuals and can occur despite normal sensitivity 

to MSG savoriness. Therefore, there are semi-independent mechanisms 

underlying sensitivity to MSG and its interactions with IMP and GMP. 

At present, there are two putative savory taste metabotropic receptors 

identified: human taste GRM4 [6p21.3] and the receptor dimer human 

TAS1R1-TAS1R3 [1p36.23; 1p36.33]. Taste GRM4 (an orally located 

splice variant of the CNS GRM4, the group lll inhibitory glutamate 

receptor) was sequenced and several identified exonic polymorphisms 

were not correlated with savory taster status. The common 

polymorphism in TAS1R3 (A5T) was also not correlated with savory 

taster status. TAS1R1 contains eight less common polymorphisms, 

including a nonsense mutation, comprising several haplotypes in our 

subjects. TAS1R1 also has four splice variants. These studies will help 

identify the receptors responsible for this quality of taste in humans. 

Research was funded by DC02995 (breslin@monell.org). 


GLUTAMATE- AND INOSINE-INDUCED CALCIUM 

RESPONSES IN MOUSE TASTE RECEPTOR CELLS 

Maruyama Y. 1, Chaudhari N. 2, Roper S.D. 2 1Physiology & Biophysics, 

University of Miami School of Medicine, Miami, FL; 2Physiology & 

Biophysics and Program in Neuroscience, University of Miami, Miami, 

FL 

L-glutamate (L-Glu) is a naturally occurring amino acid in proteinrich 

food and elicits umami taste. Umami taste is synergistically 

enhanced by nucleotides, including inosine 5'-monophosphate (IMP). 

Hypotheses proposed to explain nucleotide synergy include: 1) separate 

receptors for L-Glu and nucleotide are expressed in distinct cells and 

integration occurs at a subsequent stage, e.g. postsynaptically; 2) each 

receptor is expressed in the same taste receptor cells; 3) L-Glu and 

nucleotide interact with the same receptor. To examine whether the 

same taste cells respond to L-Glu and IMP, we measured intracellular 

Ca2+ responses to L-Glu, IMP and a mixture of both tastants in 

gustatory sensory cells loaded with Calcium Green-1 Dextran and 

imaged in slices of circumvallate papillae with confocal microscopy. 

Monopotassium glutamate (MPG, 500 mM) alone, as well as IMP (1 

mM) alone, applied focally to taste pores, induced transient [Ca2+ ] i 

responses in some taste receptor cells. To date, MPG-responsive cells 

have also responded to IMP, suggesting that glutamate and nucleotides 

act on the same receptor. Alternatively, the cognate receptors are 

expressed in the same cell and the receptor(s) do not obligatorily 

require a mixture of IMP and glutamate. Mixtures of MPG and IMP 

elicited ~3-fold larger responses than the summation of individual 

responses to MPG and IMP alone. These data indicate that nucleotide 

synergy of glutamate taste is detectable at the level of Ca2+ signals in 

individual taste cells. Supported by NIH/NIDCD grant DC03013. 

111 


BEHAVIORAL TASTE RESPONSES TO MONOSODIUM 

GLUTAMATE AND SODIUM CHLORIDE IN FOUR SPECIES 

OF NONHUMAN PRIMATES 

Hernandez Salazar L. 1, Laska M. 2 1Instituto de Neuro-Etologia, 

Universidad Veracruzana, Xalapa, Mexico; 2Department of Medical 

Psychology, University of Munich, Munich, Germany 

Taste responses of six squirrel monkeys, five pigtail macaques, four 

olive baboons and four spider monkeys to monosodium glutamate 

(MSG) and to sodium chloride were assessed in two-bottle preference 

tests of brief duration (2 min). When given the choice between tap 

water and defined concentrations of the two tastants dissolved in tap 

water, the animals were found to significantly discriminate 

concentrations of MSG as low as 2 mM (spider monkeys and olive 

baboons), 50 mM (pigtail macaques) and 300 mM (squirrel monkeys) 

from the solvent. With sodium chloride, taste preference thresholds 

were found to be 1 mM (spider monkeys), 20 mM (pigtail macaques), 

50 mM (olive baboons), and 200 mM (squirrel monkeys), respectively. 

Across-species comparisons of the degree of preference for MSG and 

sodium chloride displayed by the four primate species showed the same 

order of spider monkeys > olive baboons > pigtail macaques > squirrel 

monkeys. When presented with equimolar concentrations of different 

tastants, all four species preferred sucrose as well as a mixture of 

sucrose and sodium chloride over MSG, and – at least at one 

concentration – they preferred MSG over sodium chloride. The results 

support the assumption that the taste responses of the four primate 

species to MSG and sodium chloride might reflect an evolutionary 

adaptation to their respective dietary habits. 

421 Poster [ ] Human Olfactory Performance 

SOURCE MEMORY FOR ODORS AND OBJECTS IN 

CHILDREN AND YOUNG ADULTS 

Pirogovsky E. 1, Gilbert P. 2, Addie S. 1, Stull K. 1, Ricardo T. 1, Viera E. 1, 

Murphy C. 1 1Psychology, San Diego State University, San Diego, CA; 

2School of Medicine, University of California San Diego, San Diego, 

CA 

Recall and recognition memory for odors is poorer in children than in 

adolescents. In addition, children perform worse than young adults in 

source memory tasks using visual and auditory stimuli. However, 

source memory for odor stimuli has not been examined in children. The 

present study investigated source and item memory for odors and 

objects in children (7-10 yrs) and young adults (18-24 yrs). During the 

study phase, 1 male and 1 female experimenter (sources) randomly 

presented either 16 odors or 16 objects to the participant. Presentation 

alternated between sources so that each source presented 8 stimuli. 

Once the16 stimuli were presented, the sources exited and a third 

experimenter began the test phase. To assess item recognition memory, 

a stimulus from the study phase and a novel stimulus were presented to 

the participant who was asked to choose the stimulus presented in the 

study phase. Source memory was assessed with the 8 stimuli not used in 

the item memory task. The experimenter presented a stimulus and asked 

whether the male or female experimenter had previously presented the 

stimulus. Results indicate that for objects, source and item memory 

were similar for children and adults. For odors, item memory was 

similar for the two groups; however, source memory for odors was 

significantly poorer in children than in young adults. It has been 

suggested that the frontal lobes play a critical role in source memory 

and odor memory and that this brain region continues to develop into 

adolescence. Children´s poor performance on the source memory task 

for odors may be due in part to the immaturity of the frontal lobes. 

Supported by NIH grant #AG04085 to CM


AGE-RELATED CHANGES IN SOURCE AND ITEM MEMORY 

FOR ODORS AND OBJECTS 

Gilbert P.E. 1, Ferdon S. 2, Pirogovsky E. 2, Moreland M. 2, Owens A. 2, 

Wilkes A. 2, Murphy C. 2 1Head and Neck Surgery, University of 

California, San Diego, San Diego, CA; 2Psychology, San Diego State 

University, San Diego, CA 

Source memory is more affected by aging than item memory. 

However, little research has investigated age-related changes in source 

and item memory for olfactory stimuli. The present study compared 

source and item memory for odors and objects in healthy elderly and 

young adults. During the study phase, either 16 odors or 16 objects 

were randomly presented by a male and a female experimenter 

(sources) to the participant. Presentation alternated between sources so 

that 8 stimuli were presented by each source. Once the stimuli were 

presented, the test phase was conducted by a third experimenter. To 

assess source memory, a stimulus from the study phase was presented 

to the participant who was asked to indicate whether the stimulus was 

presented by the male or female experimenter. To assess item 

recognition memory, a stimulus from the study phase and a novel 

stimulus were presented and the participant was asked to indicate which 

stimulus was presented during the study phase. Source and item 

memory for odors and objects were similar in young adults. In elderly 

adults, source memory was impaired relative to item memory for odors 

and objects. However, the impairment in source memory relative to 

item memory for odors was significantly greater than for objects. The 

data suggest that source memory for olfactory stimuli may be 

particularly sensitive to age-related changes in the brain. Supported by 

NIH grant AG04085 to Claire Murphy and training grant DC00032 to 

Terence M. Davidson. 


AGE DEPENDENT ODOUR MEMORY AND ODOUR 

IDENTIFICATION: DIFFERENTIAL EFFECTS OF GENDER 

Møller P. 1, Wulff C. 1 1Royal Veterinary and Agricultural University, 

Frederiksberg, Denmark 

Objective: To investigate the decline of odour memory and odour 

identification with age. 

Method: Ten different well-known food odours were presented in a 

4AFC identification task to 279 subjects (78 males) younger and 229 

subjects (73 males) older than 50 years of age. Half of the subjects in 

each age group were cued to remember three of the ten odours, whereas 

the other half were not informed about the following memory task. 

Memory for the same target odours in the two groups were tested with a 

3AFC procedure, where each target odour was to be detected among 

two distractor odours. 

Results: Mann-Whitney tests of overall memory find no significant 

differences between males and females in the groups below and above 

50 years of age. If subjects are divided by the age of 60 (202 Ss older 

than 60, 68 males) elderly women outperform elderly men significantly 

(p


ODORS AND MEMORIES: THE PROUST PHENOMENON 

REVISITED 

Hudson J.A. 1, Wilson P. 2, Freyberg R. 1, Haviland-Jones J. 1 

1Psychology, Rutgers, The State University of New Jersey, Piscataway, 

NJ; 2LaSalle University., Philadelphia, PA 

The Proust phenomenon refers to the common belief that odor cues 

elicit vivid and emotional childhood memories. To test the validity of 

this phenomenon, we investigated the effects of odors alone, in the 

absence of semantic or visual cues, on autobiographic memory. 110 

participants (N=55 men, 55 women) were exposed to either a control 

(no odor) or an ambient odor (one of 3 childhood, 3 environmental or 3 

floral odors) while writing childhood and recent memories. ANOVAS 

compared emotion words, sensory references, and emphatic language 

across odor categories. We found no evidence for a Proust 

phenomenon. There was no significant difference in emotion, sensory 

qualities or emphatic language in childhood memories as a function of 

odor condition. When odor effects were obtained, they were effects of 

floral odors on recent memories, not childhood memories (all reported 

effects, p < .05). Recent memories included more positive emotion 

words in the floral odor condition as compared to all other conditions. 

Women reported less negative emotion in the floral condition for recent 

memories and men reported more sensory qualities in the floral odor 

condition. Thus, (a) childhood odors had no special effect on childhood 

memories (b) there was no overall odor effect on childhood memories; 

and (c) odors did not affect childhood memories more than recent 

memories. In contrast, recent memories were more affected by odor 

than childhood memories. 

Funded by International Flavors & Fragrances, Inc. 


ODOR CATEGORIZATION IN THE ABSENCE OR IN THE 

PRESENCE OF ODOR NAMES 

David S. 1, Rouby C. 2, Bensafi M. 2, Barkat S. 2 1CNRS UMR 7114 – 

Modyco et Université Paris 10, Paris, France; 2CNRS UMR 5020 et 

Universite Lyon1, Lyon, France 

In order to study the top-down influence of names on odor 

categorization, we compared situations allowing perceptual 

categorization which is supposed to be mainly driven by stimulus 

properties, with semantic categorization supposed to be driven by our 

knowledge. Two groups of 20 subjects were asked to form categories 

among 16 odors according to their similarity : group 1 was provided 

odor vials without any information on the name, group 2 was provided 

the same odor vials labeled with a name. A third group categorized only 

the labels, without olfactory stimuli, so relying on their memory to 

judge similarity. After the categorization task, subjects evaluated the 16 

odors again on intensity, pleasantness, familiarity and typicality. We 

stated the hypothesis that when judging real odors, the main dimension 

for odor categorization would be the hedonic valence, and that valence 

would no longer dominate when categorizing from memory. The results 

confirmed the hypothesis : hedonic ratings were correlated with the 

main dimension for groups 1 and 2, not for group 3. Results also show 

that the presence of names reduces the number of categories and that 

these categories tend to be hierarchically organized, which is not the 

case for the group 1. 

113 


CAN YOUR NOSE SHINE AN ATTENTIONAL SPOTLIGHT? 

Porter J.A. 1, Zelano C. 1, Mainland J. 1, Johnson B. 1, Bremner E. 1, Khan 

R.M. 1, Bensafi M. 1, Sobel N. 1 1Biophysics, University of California, 


Directed spatial attention in vision and audition enables heightened 

sensory acuity for events at known spatial locations. We asked whether 

a similar phenomenon exists in chemical sensing. Initially, we asked if 

humans have access to spatial information through chemosensation. We 

tested 33 subjects on a 16 trial left vs. right localization task. The 

odorants rose and strawberry (diluted 1:4 into proprionic acid) were 

generated by an air dilution olfactometer, and delivered via a divided 

nasal mask with separate left and right entry ports. As a group, subjects 

were slightly but significantly above chance in their ability to spatially 

localize the odorants (accuracy = 57.8%±2.7% t=2.841, p


DISCRIMINATING DEUTERATED FROM UNDEUTERATED 

ACETOPHENONE: COMPARING HUMANS AND A DOG 

Zelano C. 1, Rubenstein N. 1, Mainland J. 1, Porter J. 1, Bremner E. 1, 

Johnson B. 1, Khan R. 1, Sobel N. 1 1Biopyhsics, University of California, 


To determine if deuterated compounds can be distinguished from 

their undeuterated counterparts through smell, we set out to replicate a 

previous report: 31 subjects performed a one-trial same/different 

discrimination on two jars containing deuterated (D) and undeuterated 

(H) acetophenone. 24 subjects correctly chose different. However, 

when performing the same task using two identical samples of H, 23 

subjects erroneously chose different. Thus, a bias existed toward 

answering different. To avoid the bias, we used an olfactometer to test 

38 subjects in a 32 trial same/different forced choice design. Mean 

accuracy was not different from chance (52.5% ± 3.5, p>.1). To 

eliminate possible habituation effects, we repeated the task in 14 

subjects with only 8 trials. Mean accuracy was not different from 

chance (60% ± 23, p>.1). To test a different paradigm, an additional 10 

subjects performed a three-alternative forced choice identification task. 

Mean accuracy was not different from chance (38.5%±22, p>.1). 

Humans thus far unsuccessful, we set out to see if a dog could 

discriminate H from D. A German Shepard was trained to recognize H. 

He then did 7 trials of a three-alternative forced-choice identification 

task at 100% accuracy (p

Abou, Elizabeth, 309 

Abraham, Michael H., 67 

Abrell, Leif, 267 

Aburatani, Hiroyuki, 199 

Acevedo, Humberto P, 290 

Ache, Barry W, 47, 216 

Adams, Chris, 63 

Adams, Julie, 246 

Addie, Servin, 421 

Agerman, Karin, 205 

Aggio, Juan F., 216 

Ahmed, Osama, 418 

Akins, Michael, 222, 256 

Alarcon, Suzanne M, 298, 418 

Albrecht, Gudrun, 331 

Alex, James, 306 

Alimohammadi, Hessamedin, 172, 173 

Allen, Dawn, 413 

Allgood, Sallie, 171 

Alony, Ronny, 127 

Alvarez-Buylla, Arturo, 1 

Amendola, Diedra, 154 

Amer, Ahmed, 63 

Ang, Lay-Hong, 9 

Ansari, Rahman, 104 

Apkarian, Apkar Vania, 26 

Arbuckle, Wesley, 157, 284 

Arellano, Julie, 45 

Armstrong, Cheryl L. H., 30 

Arriola, Aline, 378 

Ashkenazi, Amir, 302 

Atarot, Tal, 127 

Atema, Jelle, 237, 265, 406 

Atkinson, Rachel, 371 

AtKisson, Mary S., 125 

Axel, Richard, 72 

Bachmanov, Alexander, 90, 296 

Bai, Li, 204 

Bailey, Michele L., 115 

Bailie, Jason M, 118, 120, 121 

Baird, John P, 316 

Baker, Harriet, 381 

Balderston, Catherine C, 332 

Baldwin, David, 376 

Baquero, Arian, 181 

Barbara, Cerf, 251 

Barbour, Jon, 130, 358 

Bargmann, Cornelia I., 70 

Barkat, Samy, 427 

Barnard, Joan, 245 

Barrows, Jennell, 83 

Bartoshuk, Linda M., 21, 215, 304, 305, 306, 366 

Battey, James F., 211 

Bayevsky, Alex, 319 

Beauchamp, Gary K., 13, 58, 296 

Bedner, Peter, 362 

Behan, John, 104 

115 

Beites, Crestina, 11 

Belanger, Andrea, 157 

Belanger, Rachelle M., 52, 236 

Bell, Wade E., 108 

Ben-Asher, Edna, 127 

Benard, Lumie, 182, 295 

Bensafi, Moustafa, 103, 310, 427, 428 

Benton, Richard, 357 

Bergman, Daniel A., 52, 234, 235 

Berlin, RoseAnn, 381 

Bernd, Bufe, 191, 433 

Berndtsson, Jonas, 164 

Best, Aaron Robert, 99 

Bhandawat, Vikas, 51 

Bhatt-Mackin, Seamus Michael, 26 

Bigbee, John W, 188 

Bilder, Robert M, 331 

Blake, Camille, 96 

Blakemore, Laura J., 396 

Bleich, Stefan, 414 

Blizard, David A., 369 

Blonde, Ginger D., 79 

Bobkov, Yuriy V, 47 

Bohbot, Jonathan, 136, 268 

Bomsztyk, Mayan, 208 

Bönigk, Wolfgang, 50 

Bose, Soma C., 286 

Böttger, Bärbel, 172 

Boughter, John D., 186, 318, 368 

Boughter, Jr, John D., 213 

Boyle, Julie A., 101, 102 

Bradley, Jonathan, 50, 279 

Bradley, Robert M., 92 

Brand, Joseph, 183, 328, 330 

Brann, Jessica H., 35 

Brasser, Susan M, 93, 209 

Bremner, Elizabeth, 310, 428, 430, 432 

Breslin, Paul A.S., 23, 24, 25, 166, 191, 298, 418, 433 

Breza, Joseph M., 85 

Brown, Heather J., 108 

Brunjes, Peter C., 8 

Bryant, Bruce, 170 

Buck, Linda, 311 

Buntinas, Linas, 292 

Burd, Gail, 140 

Burgess, John R., 31 

Burks, Catherine A, 74 

Buschmann-Maiworm, Regina, 123 

Byrd, Christine A., 221 

Cain, William S., 67 

Calder, Andrew J, 26 

Calhoun-Haney, Rose, 251 

Calof, Anne L., 11 

Campbell, Hannah, 17 

Cao, Jie, 328, 330 

Caprio, John, 97 

Caramanos, Zografos, 68

Carlson, John R, 129, 131 

Carlsson, Mikael, 3 

Carlton, Michelle, 62 

Carr, Virginia McM, 206 

Carson, Christine, 351 

Case, Gilbert R., 96, 275 

Cerf-Ducastel, Barbara, 303, 309 

Chalé, Angela, 31 

Chandran, Suchismita, 106, 124, 283 

Chapo, Audrey, 21, 306 

Chaudhari, Nirupa, 80, 419 

Chen, Denise, 162, 163 

Chen, Margaret, 309 

Chen, Ping, 32, 33, 278 

Chen, Wei R., 395 

Chen, Wen, 63 

Chess, Andrew, 145 

Chi, Qiuyi, 128 

Chin, Joanna, 349 

Chopra, Anita, 65 

Choudhury, Eric, 122 

Christ-Hazelhof, Elly, 15 

Christensen, Thomas, 138, 230, 403, 407 

Christiansson, Sven Åke, 164 

Christina, Kuhn, 191 

Christy, Robert C., 87, 186 

Cinelli, Angel, 33, 278 

Clapp, Tod, 184 

Clark, Larry, 271 

Cleland, Thomas, 60, 231, 232 

Clevenger, Amy C., 57 

Clyburn, Virginia L, 28 

Coelho, Daniel, 306 

Cohen, Lawrence B., 7 

Colbert, Connie L., 78, 319 

Coleman, Elaine S, 386 

Colley, Beverly Shelley, 393 

Collmann, Chad, 3, 44 

Cometto-Muniz, Jorge Enrique, 67 

Conley, David B, 337, 348 

Connelly, Timothy, 335 

Contreras, Robert J., 27, 85 

Cook, Michelle, 259 

Cooney, Janine, 42 

Corkum, Lynda, 157 

Cornelia, Hummel, 109 

Corotto, Frank Stuart, 404 

Costanzo, Richard M., 41 

Coureaud, Gerard, 312 

Cowart, Beverly J., 119, 342 

Crasto, Chiquito J, 363 

Crocker, Candice, 11 

Cunningham, Anne M., 144 

Curran, Maryanne, 58 

Curtis, Kathleen S, 27, 85 

Cusick, Matthew, 283 

Dacks, Andrew, 407 

116 

Dalton, Pamela, 116, 117, 166, 167, 176, 338, 342 

Dalton, Wang, 33 

Daly, Kevin, 216, 219, 220 

Daly, Mark, 145 

Damak, Sami, 189, 370 

Damann, Nils, 175 

Daniel, Peter Carter, 53 

Daniels, Yasmine, 38 

Danilov, Yuri, 370 

Danilova, Vicktoria, 370 

Dankulich, Luba, 291 

Darby-King, Andrea, 61 

Darmohusodo, Vincent, 361 

Davenport, Rachel A., 317 

David, Sophie, 427 

Davidson, Andrew, 304, 366 

Davis, Michael, 59 

Davison, Ian G., 224 

Day, Kristen M., 390 

De Wijk, Rene, 22, 409 

DeFazio, Richard Anthony, 81 

Delay, Eugene R., 416, 417 

Delay, Rona, 155, 280, 281, 283 

Delwiche, Jeannine, 16 

DeMarchis, Silvia, 257 

DenBleyker, Megan J., 294 

Dennis, John Carroll, 386 

Derby, Charles D., 238, 239, 247, 269, 270, 388, 389 

DeSimone, John A., 75 

Desimone, John A., 76, 82, 188 

Devanand, Devangere P., 193 

Di Lorenzo, Patricia, 88, 91 

Diamond, Jeanmarie, 166 

Dinehart, Mary E., 215 

Distel, Hans, 378 

Dittman, Andrew, 376 

Djordjevic, Jelena, 102 

Dodds, Tyler, 256, 349 

Dolensek, Jurij, 153 

Dotson, Cedrick D., 210 

Doty, Richard L., 122, 192, 195, 341, 335, 379, 411 

Dowling, Ryan S, 84 

Drago, Joan, 165 

Drayna, D., 191, 367, 433 

Duffy, Valerie B., 19, 21, 215, 304, 306, 366 

Dulchenko, Natalia, 271 

Dvoriantchikov, Guennadiy, 80 

Eisthen, Heather L., 156 

El Sharaby, Ashraf, 200 

Ennis, Matthew, 397, 398, 399 

Erdelyi, F., 397 

Erisir, Alev, 321 

Erland, Susanne, 374 

Ernfors, Patrik, 205 

Eslinger, Paul J., 104 

Essick, Greg, 65 

Eylam, Shachar, 77

Fadool, Debra, 34, 35, 64, 392, 393 

Farahbod, Haleh, 228 

Farbman, Albert I., 206, 345 

Farmer, Jennifer M, 335 

Farmer-George, Megan, 69 

Fasolo, Aldo, 257 

Fatsis, Stefan, 116 

Fee, Michale, 225 

Felber, Stefan, 331 

Feld, I, 163 

Feldman, George, 178 

Feldman, Roy S., 330 

Feldmesser, Ester, 127 

Ferdon, Sally, 251, 422 

Fernandez, Kenny, 136 

Fernando, Shahan, 44 

Findley, Leslie, 333 

Fine, Jared M., 264 

Finger, Thomas E., 83, 86, 148, 172 

Firby, Ashley E., 284 

Flecke, Christian, 375 

Fleischhacker, W Wolfgang, 331 

Fletcher, Max, 226 

Floriano, Wely B., 126, 367 

Forestell, Catherine A., 159 

Formaker, Bradley K, 84 

Foster, James D., 383 

Frank, Marion E., 84, 212, 302, 369 

Frank, Robert A., 118, 120, 121 

Frasnelli, Johannes, 109, 174, 177, 277, 339 

Freyberg, Robin, 425, 426 

Frings, Stephan, 50 

Fukami, Hideyuki, 92 

Fukuda, Nanaho, 360 

Fuller, Cynthia L., 221 

Fung, France W., 351 

Fusetani, Nobuhiro, 240 

Fushiki, Tohru, 29 

Fussnecker, Brendon L., 62 

Futschik, Thomas, 177 

Galindo-Cuspinera, Veronica, 24 

Gallagher, Michela, 308 

Garcea, Mircea, 78, 79, 319 

Gelperin, Alan, 225, 233 

Gensch, Thomas, 50 

Gent, Janneane F., 302 

George, Pravin, 300 

Gerber, Johannes C, 277 

Gerlach, Gabriele, 265, 373 

Gesteland, Robert C, 118, 120, 121 

Getchell, M. L., 346, 347 

Getchell, T. V., 346, 347 

Ghosh, Shobha, 188 

Gibson, Nicholas J., 137, 139 

Gilad, Yoav, 127 

Gilbert, Paul E, 421, 422 

117 

Gilbertson, Timothy A, 69, 74, 179, 180, 181 

Gin, Christopher, 141 

Gisselmann, Günter, 130 

Glendinning, John I, 189, 208 

Goddard, William A., 126, 367 

Goins, Michael, 307, 343 

Goldman, Aaron, 131 

Goldman, Daniel J., 221 

Gomez, George, 154, 291 

Gorman, Rachael, 280 

Gould, Fred L., 55 

Gould, Michele, 338 

Graham, Kristin, 112 

Green, Barry, 300 

Green, Elgin, 402 

Green, Mariah H., 108 

Greenaway, Peter, 374 

Greenwood, David, 42, 314 

Greer, Charles A., 222, 256, 349 

Griff, Edwin R., 400, 401 

Groot, A, 55 

Grozinger, Christina M., 372 

Guenter, Jeremy, 180 

Guerenstein, Pablo G., 267 

Guest, Steve, 65 

Gulbransen, Brian, 172 

Gunnarson, Amy, 135 

Gur, Raquel E, 332 

Gutierrez, Ranier, 94 

Haas, Lori, 309 

Haase, Lori B., 303 

Hagelin, Julie, 241, 242, 243 

Hahn, Chang Gyu, 384 

Halbich, Wolfgang, 218 

Hall, Spencer, 126 

Hallem, Elissa A., 129 

Hallock, Robert M., 88, 91 

Halpern, Bruce Peter, 429 

Halpern, Mimi, 32, 33, 38, 40, 273, 274, 278 

Hamilton, K. A., 397 

Hänel, Tobias, 174 

Hansen, Anne, 148 

Hansen, Dane R, 69, 74, 179 

Hansson, Bill, 3, 374 

Hao, Yan-Peng, 391 

Hardin, Debra, 286 

Harley, Carolyn W, 61 

Harteneck, Christian, 362 

Haskins, Mark, 291 

Hastings, Lloyd, 110 

Hatt, Hanns, 130, 168, 175, 358 

Haviland-Jones, Jeannette, 425, 426 

Hawkes, Christopher H., 196, 333 

Haxel, Boris R., 336 

Hayar, Abdallah, 397, 399 

Hayashi, Hisaki, 11 

Hayes, John, 19, 21

Heck, Gerard L, 75, 76, 82, 178, 188 

Hegg, Colleen, 254, 285 

Heidema, Johannes, 15 

Heilmann, Stefan, 130, 174, 339 

Heilmann, Stefan K., 408 

Heinbockel, Thomas, 397, 398, 399 

Heldt, Scott, 59 

Hellekant, Goran, 370 

Henion, Timothy, 377 

Henkel, Marta, 123 

Henley, Monique, 413 

Hennet, Thierry, 377 

Hernandez Salazar, Laura Teresa, 420 

Hettinger, Thomas P., 212, 369 

Higuchi, Makoto, 379 

Hildebrand, John G., 138, 230, 267, 407 

Hile, Arla, 243 

Hill, David L., 321, 322 

Hillier, Kirk N, 55, 217 

Hing, Huey K., 9 

Hingco, Edna E., 350 

Hino, Akihiro, 12 

Hinterhuber, Hartmann, 331 

Hirano, Ken-ichi, 29 

Hirsch, Alan R., 115, 344 

Ho, Michael G., 129 

Hoe, Lori, 386 

Hoffman, S M, 118 

Horner, Amy J., 238 

Horning, K A, 118 

Hornung, David, 56 

Houpt, Thomas A., 317 

Hsu, Jessie, 352 

Huang, Liquan, 183, 328 

HUANG, YI-JEN J, 329 

Hudry, Julie, 424 

Hudson, Judith A., 425, 426 

Hudson, Robyn, 378 

Huesa, Gema, 86 

Huettenbrink, Karl-Bernd, 177 

Hultine, Stacy, 58 

Hummel, Patrick A., 126 

Hummel, Thomas, 109, 130, 165, 174, 177, 277, 339, 340, 408 

Huque, Taufiqul, 330 

Hurst, Jane, 313 

Hutchinson, Ian, 253 

Hüttenbrink, Karl-Bernd, 339. 340 

Hyder, Fahmeed, 4 

Ichikawa, Masumi, 37 

Illig, Kurt R., 8 

Inoue, Masashi, 296 

Iwatsuki, Ken, 199 

Iwema, Carrie, 256, 349 

Jacobson, Aaron, 303 

Jafek, Bruce W., 114 

Jahng, Jeong Won, 320 

118 

Jakob, Ingrid, 158 

Jang, Woochan, 143 

Jean, Gotman, 334 

Jensen, Dwayne, 42 

Jeon, S-Y, 297 

Ji, Qingzhou, 182 

Jia, Changping, 40, 274 

Jia, Fan, 395 

Jiang, Peihua, 295 

Jinks, Anthony, 253 

Johns, Malcolm, 388 

Johnson, Brad, 103, 310, 364, 428, 430, 432 

Johnson, Brett Alan, 227, 228, 350 

Johnson, Paul, 269, 270 

Johnston, Megan Elizabeth, 404 

Johnston, Robert E., 315 

Jones, David, 371 

Jones, Seth V., 59 

Jones-Gotman, Marilyn K., 68, 101, 102, 334, 424 

Jordan, Melissa, 42 

Jorde, Lynn, 367 

Judd, Robert L, 386 

Julie, Hudry, 334 

Jung, Yewah, 154 

Kajii, Yuka, 29 

Kamio, Michiya, 239 

Kashyap, Manoj K, 202 

Kataoka, Hiroshi, 360 

Katdare, Ameeta, 163 

Katsuie, Yasutomi, 369 

Katsukawa, Hideo, 293 

Katz, Lawrence Charles, 5, 224 

Kauer, John S., 125, 289, 365 

Kaupp, Benjamin, 50 

Kawada, Teruo, 29 

Kawai, Takayuki, 29 

Kawauchi, Shimako, 11 

Kay, Leslie M, 380 

Keast, Russell SJ, 25, 418 

Keiser, Meagan, 107 

Keller, Andreas, 250 

Keller, Gerald S, 207 

Kemmler, Georg, 331 

Kemmotsu, Nobuko, 431 

Kennedy, Janice M., 13, 14, 214 

Kent, Lauren B., 354 

Kern, Robert C, 337, 348 

Kerr, Kara-Lynne, 379, 411 

Keshishian, Haig, 9 

Kett, Lauren, 242 

Khan, Rehan M., 103, 310, 364, 428, 430, 432 

Khen, Miriam, 127 

Kicklighter, Cynthia, 269, 270 

Kida, Ikuhiro, 4 

Kidd, Judith, 304, 366 

Kidd, Kenneth K., 304, 366 

Kim, Joon, 11

Kim, K-O, 297 

Kim, Un-kyung, 191, 367, 433 

Kim, Yoon Tae, 320 

King, Michael S, 207 

Kingsford, Michael, 265 

Kinnamon, John C., 324, 325 

Kinnamon, Sue C., 83, 184, 326 

Kinsley, Elizabeth, 215 

Kleene, Nancy Koster, 282 

Kleene, Steven J., 282 

Klein, Jeffrey T., 69, 180 

Kleineidam, Christoph J., 218 

Klimbacher, Martina, 331 

Klock, Christopher, 119 

Klupp, Barbara, 175 

Knecht, Michael, 277 

Knipe, Cheryl, 341 

Kokrashvilli, Zaza, 189 

Kong, Ji Yong, 208 

Konnerth, Claus-Günther, 340 

Koo, Jae Hyung, 385 

Kornhuber, Johannes, 414 

Kosmidis, Efstratios, 7 

Koulakov, Alexei, 233 

Kratskin, Igor, 391 

Krautwurst, Dietmar, 362 

Kremser, Christian, 331 

Kroeze, Jan H. A., 299 

Krug, Patrick, 359 

Kubanek, Julia, 239 

Kurahashi, Takashi, 46 

Kusakabe, Yuko, 12 

Kuwasako, Takahiro, 29 

Kwon, Hyun J, 150 

Kwon, Hyung-Wook, 356 

Kwong, K., 346, 347 

Labra, Antoineta L, 34 

Laflam, Timothy, 119 

Lai, Peter C., 363 

Laing, David, 253 

Lancet, Doron, 127 

Landis, Basile N, 109, 339, 340 

Lane, Robert P, 36 

Langlois, Dominique, 312 

Lanier, Sarah, 19 

Larsson, Maria, 164 

Laska, Matthias, 249, 420 

Lawless, Harry T., 301 

le Coutre, Johannes, 330 

Lechner, Theresia, 331 

Lee, H-S, 297 

Lee, Jong-Ho, 320 

Lee, Virginia M.-Y., 379 

Lehmkuhle, Mark J, 6 

Lei, Hong, 230 

Leinders-Zufall, Trese, 150 

Leininger, Elizabeth Claire, 243 

119 

Leitch, Amanda, 56 

Lemon, Christian H, 93, 209 

Leon, Michael, 227, 228, 350 

Leonard, Ong, 126 

Lewcock, Joseph W., 132 

Li, Cheng Shu, 89 

Li, Cheng Xiang, 89 

Li, Cheng-shu, 278 

Li, Weiming, 157 

Li, Xia, 296 

Liggett, Rachel, 16 

Lilley, Sarah, 252 

Liman, Emily R, 190 

Lin, Dayu, 5 

Lin, Jeff, 163 

Lin, Weihong, 45, 98 

Linardopoulou, Elena, 352 

Linn, Charles, 217, 266 

Linschoten, Miriam R., 114 

Linster, Christiane, 60, 231 

Litaudon, Philippe, 158 

Liu, Dan, 190 

Liu, Guang, 48 

Liu, H., 347 

Liu, Hong-Xiang, 197 

Liu, Nian, 4, 229 

Liu, Weimin, 32, 33, 278 

Liu, Zhan, 295 

Longo, Melissa, 20 

Lorig, Tyler S., 100 

Loudon, Catherine, 262 

Lowe, Graeme, 223 

Lowry, Catherine A, 380 

LU, KUO-SHYAN S, 329 

Lu, Lu, 368 

Lucas, Nadia, 163 

Lucero, Mary T., 49, 254, 285 

Lui, S., 418 

Lundstrom, Johan N, 160, 277 

Lunkenheimer, Birgit, 414 

Lunkenheimer, Jens, 414 

Lyall, Vijay, 75, 76, 82, 188 

Lynch, David R, 335 

Ma, Jie, 223 

Macdonald, Jessica, 141 

Mackay-Sim, Alan, 336 

Macknin, Jonathan, 379 

Maggi, Leigh, 159 

Maher, Timothy J., 63 

Maier, Claudia, 331 

Mainland, Joel, 103, 310, 428, 430, 432 

Makino, Junshiro, 369 

Man, Orna, 127 

Manda, Saraswati, 385 

Mangold, Jamie Elizabeth, 322 

Mann, Wolf, 336 

Manzini, Ivan, 152

Margolis, Frank L., 150, 151, 385 

Margolis, Joyce W., 151 

Margolskee, Robert, 182, 183, 189, 199, 295, 370 

Marks, Lawrence E., 302 

Marlicz, Wojciech, 144 

Maroldt, Heike, 339 

Marshall, Katrina, 253 

Martin, Arthur, 235 

Martínez-Gómez, Margarita, 378 

Martinez-Marcos, Alino, 40 

Maruyama, Yutaka, 419 

Mascioli, Kirsten J., 214, 418 

Mast, Thomas, 400 

Matsumura, Kouichi, 240 

Matsunaga, Shigeki, 240 

Matsunami, Hiroaki, 128 

Matsunami, Momoka, 128 

Matsuoka, Masato, 41 

Mattes, Richard D., 30, 31, 410 

Maute, Christopher, 117, 167 

Max, Marianna, 182, 183, 295 

May, Darran, 376 

May, Olivia L., 321 

Maynard, Edwin M., 6 

Mbiene, Joseph-Pascal, 198, 203 

Mc Cune, Allicia, 112 

McBride, Kathleen, 248 

McBurney, Donald H., 161 

McCann, Jennifer, 61 

McCaughey, Stuart, 90 

McClintock, Martha, 244 

McClintock, Timothy S., 286, 287, 390 

McCluskey, Lynnette Phillips, 187 

McDermott, Ryan, 176 

McGlone, Francis, 65, 68 

McIntyre, Jeremy C., 286, 287 

McKee, Sherry, 305 

McLean, John Harvey, 61 

McNamara, Ann Marie, 60 

Mead, Kristina S., 261 

Mechaber, Wendy L., 267 

Mechtcheriakov, Sergei, 331 

Medler, Kathryn, 184 

Medrano, Juan F., 330 

Meisami, Esmail, 149, 387 

Mellinger, Craig, 303 

Mellon, DeForest, 405 

Menashe, Idan, 127 

Menco, Bert, 382 

Mennella, Julie A., 13, 14, 159, 214 

Meredith, M, 96, 275 

Meredith, Michael, 276, 392 

Mettenleiter, Thomas C., 175 

Meyerhof, Wolfgang, 191, 433 

Michel, William Craig, 147 

Michele, Gould, 117 

Miklavc, Pika, 54 

Miller, Ginger, 262 

120 

Miller, Lauren, 162 

Miller, Perry L., 229 

Miller-Sims, Vanessa, 406 

Mirich, Jennifer, 8 

Mistretta, Charlotte, 197, 204 

Mitzelfelt, Jeremiah D., 417 

Miura, Hirohito, 12 

Mizutani, Makoto, 369 

Moberg, Paul J., 122, 194, 332 

Mogyorosi, Andras, 178 

Mojet, Jos, 15, 22 

Møller, Per, 423 

Moncomble, Anne-Sophie, 312 

Moon, Cheil, 142 

Moon, Young Wha, 320 

Moore, Paul A., 52, 219, 234, 235, 236, 246, 258, 259, 260 

Moreland, Molly, 422 

Morrison, Edward E, 386 

Muhammed, Nizar, 333 

Munger, Steven D., 151, 213, 318 

Murphy, Claire, 251, 303, 309, 421, 422, 431 

Murray, Sarah G, 412 

Naidenko, Sergei, 271 

Naqvi, Ferheen, 167 

Neff, Jessica K., 341 

Nelson, Gina M, 323 

Nelson, Theodore M., 213, 318 

Neuhaus, Eva Maria, 130, 358 

Neves, Guilherme, 145 

Newcomb, Richard, 42 

Newman, Tera, 36, 352 

Newth, Angela, 319 

Nguyen, Eric A, 316 

Nicholson, Donald, 351 

Nickell, Tom, 288 

Nickles, Scott P., 238 

Nicolelis, Miguel A. L., 94 

Niessen, Heiner, 362 

Nighorn, Alan, 3, 44, 403 

Nikonov, Alexandre A., 97 

Ninomiya, Yuzo, 12, 73, 185, 189, 293, 327 

Nishiduka, Taichi, 29 

Nojima, Satoshi, 266 

Nomura, Mariko, 162 

Norita, Masao, 41 

Normann, Richard A, 6 

Northup, John K., 211 

Nosrat, Christopher A., 205 

Nosrat, Irina, 205 

O'Mahony, Michael, 297 

O'Malley, Stephanie S., 305 

Obermayer, Marieluise, 218 

Okabe, Masaru, 360 

Oland, Lynne A., 139, 255 

Olender, Tzviya, 127 

Ollinger, Fred, 225

Olsson, Mats J, 160, 277 

Olsson, Shannon Bryn, 245 

Opiekun, Richard, 116, 176, 338 

Ou, Guangshuo, 135 

Overton, Michael, 64 

Owens, Alicia, 422 

Pakstis, Andrew, 304, 366 

Pan, Yunfeng, 107 

Park, Daesik, 156 

Parker, Scott, 413 

Parsons, Almetra D., 64 

Pataramekin, Piyanuch Pahn, 387 

Pause, Betina M., 101 

Pawlik, Kate, 410 

Pazour, Gregory J., 134 

Pepino, Marta Yanina, 14, 214 

Perkins, Randa M., 64, 392 

Perreau-Linck, Elizabeth, 68 

Petrides, Michael, 102 

Phan, Tam-Hao T, 75, 76, 82, 188 

Philip, Shaji, 411 

Phillips, Nicola, 68 

Pirogovsky, Eva, 421, 422 

Pitovski, Dimitri Z., 307, 343 

Pittman, Dave Wayne, 28 

Pitts, Jason, 355 

Pixley, Sarah K., 282 

Plummer, Kim, 42 

Poor, Alexander, 100 

Porter, Jess, 430 

Porter, Jessica A., 103, 310, 428, 432 

Pouliot, Sandra, 424 

Prescott, John, 17 

Preston, Robin, 107 

Preti, George, 116 

Pribitkin, Edmund, 119, 342 

Puchalski, Diana, 56 

Puche, Adam C., 257, 394 

Qi, Ming, 361 

Quan, Wei, 40 

Quinn, Eric, 258 

Radil, Tomas, 66 

Raghow, Sandeep, 318 

Raguse, Jan-Dirk, 362 

Raitcheva, Denitza, 377 

Raman, Shanmugam Achi, 39 

Rasmussen, LEL, 42, 241, 242, 272, 314 

Raudenbush, Bryan, 111, 112, 113, 252 

Rawson, Ashley, 113 

Rawson, Nancy E., 291, 384 

Ray, Anandasankar, 131 

Ray, Koela, 106 

Reddy, Krishna, 411 

Reden, Jens, 177 

Redman, Christopher, 234 

121 

Reed, Danielle R., 191, 214, 296, 298, 304, 366, 418, 433 

Reed, Randall R., 132 

Reisenman, Carolina E, 138, 230 

Reisert, Johannes, 51, 279 

Reneerkens, Jeroen, 241 

Resasco, Marilina, 396 

Ressler, Kerry J, 59 

Restrepo, Diego, 2, 4, 45, 57, 98, 146, 292 

Ricardo, Torres, 421 

Richardson, Anne, 104 

Richter, Trevor A., 80, 81, 210 

Riddle, Scott W, 272 

Riffell, Jeffrey A., 130, 358, 359 

Rigdon, Megan, 100 

Rigsby, Christine' Spring, 187 

Rinberg, Dima, 225, 233 

Roalf, David R., 332 

Roberts, Cherie, 17 

Roberts, Richard, 128 

Robertson, Hugh M., 354 

Robinson, Alan M, 337, 348 

Robinson, Gene E., 372 

Rochlin, M. William, 201, 202 

Roeder, Hendrikje, 272 

Roelofs, Wendell, 266 

Roessler, Wolfgang, 218 

Rogers, Daniel H, 361 

Rogers, Jessica Lee, 404 

Rong, Minqing, 189 

Ronnett, Gabriele V., 142 

Roper, Stephen D., 80, 81, 210, 329, 419 

Rosen, David, 119, 342 

Rosenthal, Allison, 180 

Roskams, Angela Jane, 141, 351 

Ross, Susan R, 58 

Rossi, Ferdinando, 257 

Rossier, Olivier, 330 

Rothman, Douglas L., 4 

Rouby, Catherine, 427 

Rubenstein, Nicola, 430 

Rubrum, Adam M., 87 

Rugai, Nick, 91 

Rupp, Claudia I, 331 

Rützler, Michael, 43, 355 

Rybalsky, Konstantin, 118, 120, 121 

Sadamitsu, Chiharu, 73 

Saddoris, Michael P, 308 

Sainz, Eduardo, 211 

Saito, Harumi, 128 

Sakata, Yoko, 147 

Salcedo, Ernesto, 146 

Saldanha, Jason, 201 

Saleh, Maya, 351 

Sammeta, Neeraja, 287 

Samuelsen, Chad L., 276 

Sandra, Pouliot, 334

Sanematsu, Keisuke, 185 

Santos, Rosaysela, 11 

Sasaki, Hayato, 381 

Schaal, Benoist, 158, 312 

Schafer, Michele, 4 

Schannen, Andrew P., 281 

Scherer, Peter W, 342 

Schiffman, Susan S, 412 

Schild, Detlev, 152 

Schlabeck, Martin, 414 

Schlador, Michael, 352 

Schmidt, Katrina C, 324 

Schmidt, Manfred, 247, 389 

Schmiedeberg, Kristin, 362 

Schoenbaum, Geoffrey, 308 

Scholey, Jonathan M., 135 

Scholtz, Arne W, 331 

Scholz, Nathaniel, 376 

Schuckel, Julia, 375 

Schuler, Amanda, 113 

Schüler, Jenny, 164 

Schurian, Walter, 123 

Schwane, Katlen, 130, 358 

Schwarting, Gary, 377 

Schwob, James E, 143 

Scott, Alexander P., 157 

Scott, John W, 290, 402 

Seiden, Allen, 120 

Sethupathy, Praveen, 232 

Shabani, Shkelzen, 269 

Shah, Mussadiq, 333 

Shangari, Gopal Krishan, 429 

Shao, Zouyi, 394 

Shaw - Taylor, Ewurama E., 244 

Shepherd, Gordon M., 4, 229, 363, 395 

Sherrill, Lisa, 402 

Shetty, Ranjit S, 287 

Shigemura, Noriatsu, 73, 327 

Shigeoka, Yuko, 327 

Shingai, Tomio, 29 

Shipley, Michael T., 394, 399 

Shiraiwa, Takashi, 131 

Shirokova, Elena, 362 

Shoup, Melanie L., 161 

Shtoyerman, Eran, 224 

Shusterman, Dennis J., 169 

Sicard, Gilles, 158 

Silman, Eric, 11 

Silver, Wayne L., 171, 172, 173 

Simon, Sidney Arthur, 69, 94 

Simpson, P Jeanette, 142 

Singer, Michael, 363 

Sitthichai, Arie A., 49 

Siwicki, Kathleen K., 375 

Slack, Jay, 191, 433 

Slotnick, Burton, 45, 248 

Small, Dana M, 26, 68 

Smeets, Monique, 22, 116 

122 

Smith, Brian H., 62, 220, 262 

Smith, David V, 87, 89, 93, 186, 209 

Smith, Dean, 371 

Smith, James C., 294 

Smith, Jeffrey, 111, 112 

Smith, Melissa Anne, 287 

Smith, Michael B., 104 

Smith, Patrick, 294 

Snow, Joshua, 135 

Snyder, Derek, 304, 305, 306, 366 

Snyder, Lenore, 182, 295 

Sobel, Noam, 103, 310, 364, 428, 430, 432 

Soleimani, Manoocher, 282 

Sollars, Suzanne I, 206 

Sorensen, Peter W., 263, 264 

Spec, Andrej, 202 

Spector, Alan C., 77, 78, 79, 210, 319 

Speed, William, 304, 366 

Spehr, Jennifer, 168 

Spehr, Marc, 130, 168, 358 

Spielman, Andrew I., 330 

Spray, Kristina J, 181 

St. John, Steven J, 316, 368 

St. John, Steven James, 318 

Stakic, Josif, 401 

Stange, Gert, 267 

Stein, Heather, 138 

Steinbach, Molly Ann, 237 

Stengl, Monika, 375 

Stensmyr, Marcus C, 374 

Stepanyan, Ruben, 390 

Stepanyan, Tracy D., 390 

Stern, Shai, 127 

Stevens, David A., 301 

Stone, Leslie M, 326 

Stratford, Jennifer M, 27 

Streeter, Sybil A., 161 

Stromberg, A. J., 347 

Stull, Kimberly, 421 

Suarez, Joseph C., 415 

Suchanek, Jessica, 401 

Sugita, Daigo, 293 

Suhr, Steven T., 221 

Sullivan, Daniel, 383 

Sullivan, Susan L., 211 

Swyers, Sarah, 386 

Szabo, Gabor, 394, 397 

Szeszko, Philip R, 331 

Tabert, Matthias H., 193 

Tai, P.C., 270, 388 

Takeuchi, Hiroko, 46 

Talamo, Barbara R., 48 

Tarun, Alice, 169 

Taylor, Gordon E., 350 

Taylor, Polly A, 294 

Taylor-Burds, Carol C., 416 

Tepper, Beverly J, 18

Tetsuya, Ookura, 12 

Tharp, Anilet A., 298 

Tharp, Christopher D., 23, 191, 298, 418, 433 

Thomas, Stacey, 325 

Thompson, Roger N., 64 

Thuerauf, Norbert, 414 

Tolbert, Leslie P, 137, 139 

Tordoff, Michael G, 296 

Touhara, Kazushige, 360 

Tourbier, Isabelle A., 335 

Trask, Barbara J., 36, 352 

Treloar, Helen B., 256 

Trojanowski, John, 379 

Trombley, Paul Q., 396 

Tucker, Kristal, 392 

Turetsky, Bruce I, 194, 332 

Turri, Linda, 245 

Ueda, Katsura, 200 

Uemura, Tadashi, 9 

Uflacker, Andre B, 207 

Umeh, Yvonne, 162 

Umezawa, Hidehiko, 369 

Urban, Lenka, 260 

Vaidehi, Nagarajan, 126 

Vainius, Aldona, 66 

Vaishnav, R. A., 346, 347 

Valentincic, Tine, 54, 153 

Valentine, Megan, 105 

van der Goes van Naters, Wynand, 131 

Van Houten, Judith, 105, 106, 107, 124, 283 

Veldhuizen, Maria Geraldine, 299 

Verret, Travis, 280 

Vetter, Monica L., 10 

Vickers, Neil J., 55, 217 

Viera, Erin, 421 

Vieyra, Michelle, 353 

Vigers, Alison, 83 

Vilbig, Ryan, 201 

Villarreal, Rebecca, 162 

Vinnikova, Anna K, 76, 82, 188 

Visegrady, Andras, 393 

Vogalis, Fivos, 254, 285 

Vogt, Richard G., 136, 268, 353 

Vosshall, Leslie B, 250, 357 

Voznessenskaya, Vera, 271 

Vrieze, Lance A., 263 

Vucinic, Dejan, 7 

Wada, Yumiko, 369 

Wakabayashi, Yoshihiro, 37 

Wakisaka, Sayoshi, 200 

Walch, Thomas, 331 

Walker, Dianne, 415 

Walker, James, 415 

Walker, Megan, 352 

Walters, Eric, 198 

123 

Walworth, Ellen, 140 

Wang, Dalton, 32, 278 

Wang, Hong, 183 

Wang, Jian-li, 104 

Wang, Jing, 72 

Warren, Craig B., 361 

Watanabe, Akira, 199 

Waters, Robert S, 89 

Watson, Erika L, 412 

Weenen, Hugo, 22, 409 

Weeraratne, Shyamal Dilhan, 105, 124 

Weiler, Elke, 345 

Weinrich, Karl, 63 

Welge-Lüssen, Antje, 165 

Westberry, Jenne, 96, 276 

Westburg, Anna M., 416, 417 

Westerterp, Margriet, 22 

Wetzel, Christian, 168, 175 

White, Joel E., 125, 289, 365 

White, Theresa L., 20 

Whitt, Robert, 415 

Wifall, Timothy C., 416 

Wilkes, Annie, 422 

Willander, Johan Magnus, 164 

Willecke, Klaus, 362 

Williams, Eleanor, 352 

Williams, Jayme Melissa, 404 

Williams, Lloyd B., 125, 365 

Williams, Robert W., 368 

Wilson, Caroline, 403 

Wilson, Donald, 226 

Wilson, Donald A., 95, 99 

Wilson, Patricia, 425, 426 

Wilson, Tracy, 110 

Winnig, Marcel, 191 

Wirkus, Eric, 154 

Wirsig-Wiechmann, Celeste Renee, 155 

Wise, Paul, 66 

Witman, George B., 133 

Wolf, Mary, 219, 258 

Wolfensberger, Markus, 165 

Wong, Allan M, 72 

Woo, Cynthia C., 350 

Woo, Jinkyeung, 143 

Wooding, Stephen, 367 

Wright, Geraldine, 62 

Wright, James C, 386 

Wulff, Christian, 423 

Wysocki, Charles, 66 

Wysocki, Linda M., 291 

Xu, Fuqiang, 4, 229 

Xu, PingXi, 371 

Yamada, Ayako, 293 

Yamashita, Shizuya, 29 

Yamazaki, Kunio, 58 

Yamout, Adam, 202

Yang, Hsiuchin, 270 

Yang, Qing X., 104 

Yang, Ruibiao, 324, 325 

Yano, J., 105, 107 

Yano, Junji, 106, 124 

Yao, Ying, 9 

Yasumatsu, Keiko, 73, 189, 327 

Yau, King-Wai, 50, 51, 279 

Ye, Mi Kyung, 87 

Yee, Karen K., 384 

Yomogida, Kentaro, 360 

Yoshida, Ryusuke, 73, 185 

Young, Janet, 36 

Young, Janet M., 352 

Yu, Katie, 157 

Yu, Tun-Tzu, 286, 287 

Yue, Esther, 60 

Yun, Sang Seon, 157 

Yurchenko, Olga, 155 

Zald, David H., 68 

Zatorre, Robert, 101 

Zatorre, Robert J, 102 

Zelano, Christina, 103, 310, 428, 430, 432 

Zellner, Debra, 413 

Zhang, Chunbo, 2, 292 

Zhang, Jianhua, 282 

Zhao, Haiqing, 151 

Zhao, Kai, 342 

Zhao, Liqiang, 18 

Zhu, Mingyan, 398 

Zhukovskaya, Marianna, 107 

Zielinski, Barbara S., 157, 284 

Zimmer, Richard K., 130, 358, 359 

Zoladz, Phillip, 252 

Zou, Zhihua, 311 

Zucker, Jacob, 145 

Zufall, Frank, 150 

Zuker, Charles S., 71 

Zulandt, Thomas John, 258 

Zuri, Ido, 38, 273 

Zwiebel, Laurence J., 43, 355, 356 

124

Givaudan-Roure Lecture - Association for Chemoreception Sciences

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