Significant strides have been made in our understanding of the initial events of sensory transduction in taste cells during the last two decades, yet little is known about the mechanisms of intercellular communication within the taste bud. Only one-fifth of the taste cells in a mouse taste bud have morphologically identifiable """"""""classical"""""""" synapses from the taste cell onto an afferent nerve fiber. Little, however, is known about the molecular features of neurotransmitter release at these sites in taste cells.It is significant that not all taste cells thought to play a role in sensory transduction have classical synapses. Taste cells that display gustducin immunoreactivity respond to bitter compounds, yet our preliminary data suggest that they do not have classical synapses onto nerve processes. How then does information pass from these bitter-sensing cells to the central nervous system? We have observed taste cells in the mouse that have unusual contacts with nerve processes in which subsurface cistemae (SSC) of smooth endoplasmic reticulum or large, atypical mitochondria with tubular cristae are located only at the close appositions with nerve processes. This proposal explores the possibility that these zones of close apposition may serve as nonclassical synapses, i.e., zones where information is transmitted from taste cells to nerve fibers via mechanisms other than the classical synapses.The goal of this grant application is to test the hypothesis that both classical synapses and non-classical taste cell-nerve fiber contacts are important in transmission of gustatory information from taste cell to nerve fiber. During the next funding period we will utilize immunocytochemistry, in situ hybridization and electron microscopy to investigate both classical and novel contacts between taste cells and nerve fibers to accomplish the following aims:
Specific Aim 1. What molecular machinery is present at morphologically unclassical synapses? Specific Aim 2. What is the nature of nontraditional taste cell-nerve fiber contacts?

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
5R01DC000285-17
Application #
6904696
Study Section
Integrative, Functional and Cognitive Neuroscience 8 (IFCN)
Program Officer
Davis, Barry
Project Start
1990-04-01
Project End
2007-06-30
Budget Start
2005-07-01
Budget End
2006-06-30
Support Year
17
Fiscal Year
2005
Total Cost
$258,830
Indirect Cost
Name
University of Denver
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
007431760
City
Denver
State
CO
Country
United States
Zip Code
80208
Bond, Amanda; Kinnamon, John C (2013) Microwave processing of gustatory tissues for immunohistochemistry. J Neurosci Methods 215:132-8