Abstracts - Association for Chemoreception Sciences

POSTER PRESENTATIONS
#P1 POSTER SESSION I: TASTE IMAGING &
PSYCHOPHYSICS; CENTRAL TASTE;
MULTIPLE MODALITIES; CENTRAL &
PERIPHERAL OLFACTION
Bitter Taste can Induce Nausea
Catherine Peyrot des Gachons 1 , Gary K. Beauchamp 1 ,
Kenneth L. Koch 2 , Robert M. Stern 3 , Paul A.S. Breslin 1
1
Monell Chemical Senses Center Philadelphia, PA, USA, 2 Wake
Forest University Winston-Salem, NC, USA, 3 Pennsylvania State
University University Park, PA, USA
In this study we show that acute oral exposure to bitter tasting
solutions can directly elicit nausea. Teleologically nausea is the
negative experience that punishes the ingestion of toxins. Since
many toxins taste bitter, there is a rational link between tasting
toxins in the mouth and the nausea that results from their
ingestion and ensuing illness. Furthermore, bitter taste is strongly
sensed by the glossopharyngeal and vagus nerves, which innervate
the posterior oral cavity and the gastrointestinal tract respectively.
The two projection fields of these sensory nerves are immediately
adjacent within the nucleus of the solitary tract as well as in other
brain relays, thus establishing a neuro-anatomical substrate for
taste inputs to influence gastro-intestinal states. To demonstrate
that oral exposures to bitter taste stimuli alone are capable of
inducing nausea, we used both subjective and objective
assessments. Healthy subjects were presented with strong bitter
taste stimuli in an oral stimulation protocol without swallowing
(0.8 uM sucrose octa-acetate hold in the mouth for 3 min). Nausea
was then measured by self-assessment on a modified Muth
Nausea Profile questionnaire and by the physiological measures
of electrogastrography (EGG). Both the questionnaire and the
EGG measurements established a nausea response to strong bitter
taste, in about 50% of the subjects tested. Sucrose solution and
water were used as controls. We therefore demonstrated for the
first time that bitter taste alone can elicit nausea in many people.
The establishment of this phenomenon is of human health
relevance as many very bitter life-saving drugs elicit gagging and
intense rejection, sometimes leading to treatment failure,
especially among children. Acknowledgements: NIH DC06760
#P2 POSTER SESSION I: TASTE IMAGING &
PSYCHOPHYSICS; CENTRAL TASTE;
MULTIPLE MODALITIES; CENTRAL &
PERIPHERAL OLFACTION
NIH Toolbox: Proposed Assessment of Taste Function and
Phenotype
Shristi Rawal 1 , Linda M. Bartoshuk 2 , Susan E. Coldwell 3 ,
John E. Hayes 4 , Howard J. Hoffman 5 , Katyrna R. Minski 1 ,
Gregory S. Smutzer 6 , Valerie B. Duffy 1
1
Allied Health Sciences, University of Connecticut Storrs, CT,
USA, 2 UF Center for Smell and Taste Gainesville, FL, USA,
3
Dental Public Health Sciences, University of Washington Seattle,
WA, USA, 4 Food Science, Penn State University State College, PA,
USA, 5 National Institute on Deafness and Other Communication
Disorders, NIH Bethesda, MD, USA, 6 Biology, Temple University
Philadelphia, PA, USA
The NIH Toolbox initiative aims to assemble brief,
comprehensive tools for population studies. We proposed
assessment of taste function and phenotype with the general
Labeled Magnitude Scale (gLMS) to quantify regional (tongue tip
chorda tympani nerve; CTN) and whole mouth intensity of water,
quinine, NaCl and propylthiouracil (PROP; whole only). In a
counter-balanced design with a sample of 100 healthy adults (18-
30 yrs, 59 F), we compared the Toolbox to existing tests: lower
QHCl level (0.3 vs 1mM) and PROP solutions vs taste strips. In
the gLMS orientation, all Ss correctly ranked remembered sound
and light sensations from weakest to strongest. Compared with a
larger control and patient database, our sample had higher quinine
ratings from CTN stimulation. Correlations across methods
ranged from 0.50 to 0.57 (water to quinine); but the Toolbox test
with the lower quinine level was more likely to classify Ss as low
functioning. Whole mouth correlations were higher across
methods (0.70 to 0.76, water to quinine). The sample was diverse
in PROP tasting. The 3.2mM PROP solution and 600nmole
PROP strip were correlated (0.59), but the solution corresponded
better to non, medium and supertaster groups based on historical
PROP to NaCl intensity ratio method. Quinine was modestly
correlated with PROP (0.22 and 0.40 for 0.3 and 1mM), but some
Ss were discordant, consistent with multiple bitter receptors. Ss
reporting greater bitterness for weak PROP concentrations also
reported greater intensities for blank control strips. In summary,
the Toolbox tests captured variability in taste function and
phenotype. The higher QHCl level may avoid misclassifying taste
dysfunction. The taste strips were more convenient but solutions
may deliver cleaner phenotypes due to less oral sensations from
the carrier media. Acknowledgements: NIH HHS-N-260-2006
00007-C, USDA Hatch Project CONS00827, NIH-NIA,
NIDCD DC000283 and DC007291
P O S T E R S
Abstracts are printed as submitted by the author(s)
Abstracts | 27