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sweetness in the Sip condition but not in the Dip condition, where
adaptation was rapid for both stimuli. In exp. 2, 20 Ss again rated
perceived sweetness in the Dip condition when the sucrose and
saccharin solutions were either 22° or 37°C. The results confirmed
the similar rapid adaptation rates for both stimuli at 22°C and
further showed that saccharin sweetness also adapted rapidly at
37°C. These results support the hypothesis that the rate of
adaptation to saccharin sweetness is independent of temperature,
and thus raise the possibility that saccharin and sucrose interact
with the TAS1R2-TAS1R3 heterodimer in ways that are
differentially sensitive to heat. Acknowledgements: Supported by
NIH grant RO1-DC005002
#P154
POSTER SESSION IV:
CHEMICAL SIGNALING & BEHAVIOR;
PSYCHOPHYSICS; CHEMOSENSATION & DISEASE;
OLFACTION PERIPHERY; TASTE PERIPHERY
The Effect of Solution Temperature on Adaptation and
Recovery of Sucrose Sweetness
Danielle J Nachtigal
1
, Barry G Green
1,2
1
The John B. Pierce Laboratory New Haven, CT, USA,
2
Yale University School of Medicine New Haven, CT, USA
In a recent study we observed that the sweetness of sucrose sensed
by dipping the tongue tip into a room temperature solution
(ca. 22°C) adapted almost completely after only a few seconds, yet
sweetness was largely restored when the tongue was retracted back
into the mouth. After a follow-up experiment demonstrated that
sucrose adaptation was temperature dependent, i.e., sweetness
adapted more rapidly when the tongue was dipped into a 22°C
solution compared to a 37°C solution, we hypothesized that the
increase in sweetness when the tongue was retracted into the mouth
was due in part to re-warming of the sucrose solution and the
tongue. The present experiment tested this hypothesis by
determining whether sweetness adaptation that occurs when the
tongue tip is dipped into a 22°C solution can be reversed by
immediately dipping the tongue tip into a 37°C solution.
Twenty-six Ss used the gLMS to rate the sweetness intensity of a
0.42 M sucrose test solution at 22° or 37°C when it was sampled
for 3 sec after 0-, 3-, 7- or 15-sec exposures to the same sucrose
solution (self-adaptation) at one of the same 2 temperatures.
The results supported the hypothesis: the measured amount of
adaptation depended more on the temperature of the test solution
than on the temperature of the adapting solution. Specifically, after
15 sec, measured adaptation was always significantly less when the
test solution was 37°C than when it was 22°C, irrespective of
whether the adapting solution was 37° or 22°C. Experiments are
continuing that are aimed at testing the hypothesis that persistence
of the sweetness of sucrose and other sugars is maximal at or near
normal oral temperature. Acknowledgements: Supported by NIH
grant RO1 DC005002
#P155
POSTER SESSION IV:
CHEMICAL SIGNALING & BEHAVIOR;
PSYCHOPHYSICS; CHEMOSENSATION & DISEASE;
OLFACTION PERIPHERY; TASTE PERIPHERY
Amifostine Alleviates Cyclophosphamide Induced
Taste Disturbances
Nabanita Mukherjee, Brittany L. Carroll, David C. Harris,
Eugene R. Delay
University of Vermont Burlington, VT, USA
Cyclophosphamide (CYP) is a commonly prescribed chemotherapy
drug. It is a DNA alkylating agent that indiscriminately attacks
proliferating cells. Like other chemotherapy drugs, CYP also has
adverse side effects such as taste disturbances which can lead to
malnutrition and poorer recovery. Amifostine (AMF) is an
approved cyto-protective adjuvant used in combination with
radiation therapy or chemotherapy (Kemp et al., 1996). AMF has
been shown to be effective in preventing radiation-induced side
effects like mucositis, nephrotoxicity, xerostomia, etc., but it has
never been tested for chemotherapy-induced disruptions of taste.
Our previous work with male C57BL/6J mice, using behavioral
methods, indicated that CYP (IP, 75mg/kg body wt) causes a two-
phase taste disturbance. The first phase lasts up to 4 days after
injection, followed by the second phase occurring during days 9-12
after injection. The first phase was due to the cytotoxic effect of
CYP on fungiform taste buds and von-Ebner glands while the
second phase was due to disruption in the taste cell replacement
cycle (Mukherjee & Delay, 2011). We hypothesized that AMF will
alleviate the CYP-induced taste disturbances. We used behavioral
and IHC methods to test our hypothesis. Sucrose detection
threshold tests indicated that pre-treatment with AMF (SC, 100
mg/kg body wt) 30 min prior to CYP injection reduces the
elevation in detection threshold of sucrose caused by CYP. It also
protected against the loss of fungiform papilla and prevented the
disruption of the fungiform taste buds observed 4 days after CYP
injection. AMF also partially protected the proliferative pool of
cells in the lingual epithelium and taste buds thought to be
responsible for normal taste sensory cell replacement.
Acknowledgements: This work is funded by NSF grant IOS-
0951016 and by Ajinomoto 3ARP.
#P156
POSTER SESSION IV:
CHEMICAL SIGNALING & BEHAVIOR;
PSYCHOPHYSICS; CHEMOSENSATION & DISEASE;
OLFACTION PERIPHERY; TASTE PERIPHERY
Salt Taste Perception in Mice with a Tissue-Specific
Conditional Targeted Mutation of the ENaCα Gene
Theodore M. Nelson
1
, Natalia P. Bosak
1
, Edith Hummler
2
,
Alexander A. Bachmanov
1
1
Monell Chemical Senses Center Philadelphia, PA, USA,
2
Pharmacology and Toxicology Department, Faculty of Biology
and Medicine, University of Lausanne Lausanne, Switzerland
Mice with the ENaCα subunit selectively eliminated in taste tissues
(ENaC-KO mice) lack the amiloride-sensitive component of chorda
tympani nerve responses to sodium salts (Bosak et al., 2010;
Chandrashekar et al., 2010). To elucidate contribution of the ENaC-
dependent mechanism to perception of salt taste, we examined
behavioral taste responses to salts in these mice. In the two-bottle
preference tests, water-replete ENaC-KO mice had elevated NaCl
preferences for weaker NaCl concentrations. In the brief-access
tests, water-restricted ENaC-KO mice had weaker NaCl avoidance
Abstracts | 79
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