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16 | AChemS Abstracts 2012
Abstracts are printed as submitted by the author(s)
made from the olfactory bulb and anterior PCX before, during and
after LEC stimulation (electrical or optogenetic) or LEC reversible
lesions (muscimol infusions, 500µg). Both spontaneous and odor-
evoked activity was quantified, including single-unit odor receptive
field characteristics. In addition, in separate animals LEC single-
unit odor receptive fields were characterized and compared with
PCX. The results suggest that LEC single-units are more narrowly
tuned than aPCX units. Furthermore, LEC activity suppresses PCX
activity, and release from this inhibition can modify PCX single-
unit odor receptive field characteristics. Given the known function
of LEC in working memory and multisensory integration, these
results suggest it may serve as a powerful top-down modulator of
olfactory cortical function, odor perception and odor memory.
Acknowledgements: NIDCD, DC03906 NIA, AG037693
NIMH, MH067763
#21
SYMPOSIUM:
CHEMICAL SENSES IN HEALTH & DISEASE
Taste Gene Polymorphism, Dietary Behaviors and Health
Valerie B Duffy
University of Connecticut/Allied Health Sciences Storrs, CT, USA
Genetic variation in taste influences food sensations, driving food
choices and possibly satiety responses, which ultimately impact
body weight and health. Associations between bitter receptor SNPs
and preference/intake for alcohol and vegetables, and related
diseases, have been most studied. Yet, single polymorphism, diet
and health relationships are observed inconsistently, suggesting this
initial research was top-down and reductionist. Environmental
factors affect receptor expression and functionality of the taste
system beyond receptor-ligand binding. Are there polymorphisms
related to this regulation? For example, we observed
TAS1R1
-
intronic SNP effects on perceived intensity across prototypical
tastants and irritants. The taste-diet-health relationship also is
affected by multiple polymorphisms. We found that
TAS2R38
nontasters consumed vegetables more frequently than
TAS2R38
tasters; the effects were more pronounced when accounting for
fungiform papillae number. Similarly, sAC gene effects on sucrose
and quinine intensity were larger in propylthiouracil tasters than in
nontasters. Inaccuracies in measuring dietary intake confound this
research. Increased attention to assessing food preference may
advance understanding of chemosensory influences on health.
Preference is easy to measure and may capture what is habitually
consumed. The full impact of chemosensory-related genes on diet
for preventing chronic diseases such as obesity, diabetes and cancer
will be realized through multidisciplinary collaborations and large,
representative datasets with careful psychophysical, nutrition and
genetic measures. These findings will inform interventions that
promote food enjoyment, satisfaction and health; optimize food and
pharmaceutical palatability; and identify novel behavioral and
disease biomarkers. Acknowledgements: United States Department
of Agriculture Hatch Project CONS00827 funds and the National
Institutes of Health DC008613
#22
SYMPOSIUM:
CHEMICAL SENSES IN HEALTH & DISEASE
Experimental Models of Compensation Following Regional
Oral Sensory Damage
Derek J. Snyder
1
, Frank A. Catalanotto
2
, Linda M. Bartoshuk
2
1
San Diego State University San Diego, CA, USA,
2
University of Florida Gainesville, FL, USA
Four cranial nerves carry oral sensory cues, and mounting evidence
indicates that these inputs interact centrally to sustain whole-mouth
sensation following regional loss. Consistent with clinical
observations, psychophysical data show that local oral sensory
anesthesia leads to compensatory disinhibition at remaining oral
loci. While several reports have found that chorda tympani (CT)
block augments glossopharyngeal (IX) sensation, selective
enhancement of trigeminal (V) sensation among supertasters of
6-n-propylthiouracil (PROP) suggests that oral disinhibition occurs
in proportion to genetic taste status. Recent work supports this
view, as unilateral CT block produces insufficient compensation in
nontasters to maintain whole-mouth taste; effects on the posterior
tongue include asymmetric taste loss and uniform oral burn loss,
but contralateral trigeminal function is unaffected. Because oral
sensation guides flavor perception and localization, the effects of
regional oral anesthesia extend to retronasal olfaction (but not to
orthonasal olfaction): Following CT block, retronasal localization
shifts to intact regions of the mouth, retronasal intensity aligns
closely with whole-mouth taste intensity, and individuals with low
taste function (e.g., T2R38 nontaster haplotypes, pre-existing oral
sensory damage) perceive the weakest retronasal cues. Taken
together, these findings demonstrate robust individual differences
in the impact of localized oral sensory loss on subsequent taste and
flavor perception: Supertasters may experience whole-mouth
constancy, while nontasters may consistently fail to achieve it.
This variation may contribute to long-term dietary and behavioral
health outcomes, and it may explain widespread inconsistency in
the clinical literature regarding oral sensory dysfunction.
Acknowledgements: NIH DC 00283
#23
SYMPOSIUM:
CHEMICAL SENSES IN HEALTH & DISEASE
Clinical Examples of Damage to Taste Nerves: Chorda
Tympani and Glossopharyngeal Nerves
Linda M. Bartoshuk
1
, Derek J. Snyder
1,2
, Frank A. Catalanotto
1
,
Howard J. Hoffman
3
, Henrietta I. Logan
1
1
University of Florida Center for Smell and Taste Gainesville, FL,
USA,
2
San Diego State University San Diego, CA, USA,
3
NIDCD, NIH Bethesda, MD, USA
Anesthesia studies show that taste and retronasal olfactory
sensations (i.e., olfactory sensations evoked by foods in the mouth)
are affected by central interactions among the neural inputs from
the oral/nasal cavity. Previous work has established that inhibition
produced at the central termination of the chorda tympani taste
nerve normally inhibits areas receiving input from other cranial
nerves. Thus reduced chorda tympani input (anesthesia, clinical
damage) can result in intensification of some oral sensations.
Anesthesia abolishes all input from the anesthetized nerve; clinical
damage diminishes input but does not usually totally abolish it.
Otitis media damages the chorda tympani nerve (CN VII);
tonsillectomy damages the glossopharyngeal nerve (CN IX).
Studies of these two pathologies permit comparisons of partial
damage to the chorda tympani, the glossopharyngeal, or both
O R A L A B S T R A C T S