Taste is initiated when sapid stimuli interact with receptor sites on the apical membrane of taste receptor cells. This ultimately leads to an increase in intracellular calcium and release of transmitter onto gustatory afferent nerve fibers. The role of the taste cell specific G-protein, gustducin, in coupling bitter stimuli with taste cell response will be examined using a transgenic line of mice in which the gustducin promoter has been linked to the gene for Green Fluorescent Protein (GFP). In these mice, cells expressing gustducin will also express GFP and can be readily identified for functional studies by their fluorescence. A combination of Ca2+-imaging and patch-clamp recording will be used to examine the role of gustducin in bitter taste transduction.
Aim 1 will determine if bitter taste responses are limited to gustducin-expressing taste cells, identify which second messenger pathways are involved in this process and assess the specific role of gustducin.
Aim 2 will identify which, if any, membrane conductances are activated or modulated by bitter stimuli.
Aim 3 will determine if a subset of taste cells is specifically tuned to bitter stimuli and if the same taste cells respond to different types of bitter stimuli. The results of these studies will reveal important insights about the role of gustducin in the transduction and coding of bitter taste.

National Institute of Health (NIH)
National Institute on Deafness and Other Communication Disorders (NIDCD)
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Special Emphasis Panel (ZRG1-IFCN-4 (01))
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Colorado State University-Fort Collins
Schools of Veterinary Medicine
Fort Collins
United States
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