Recent findings indicate that taste buds are much more complex than previously held. Mature taste cells display diverse properties and may communicate among themselves. There are suggestions that chemo-sensory detection by taste receptors is followed by a shaping of the sensory signal within the taste bud prior to transmission to the brain, much as occurs in other sensory system. Yet, the significance of cellular heterogeneity and intercellular signals within the taste bud remain to be explained. We will ask the following questions focused on the most prevalent cells in taste buds, the glial-like Type I cells: 1. Do Type I taste cells regulate the ionic environment in taste buds? Spatially buffering K+ is a key function performed by astrocytes in the CNS. Our data suggest that ROMK and certain other apical channels may form such a K+ clearance pathway in taste buds. We will use confocal Ca imaging of taste buds in lingual slices, afferent nerve recordings and behavioral assays to test the effects of K+ accumulation using physiological, pharmacological, and genetic manipulations of ROMK and other regulators of K+ efflux. 2. Do Type I taste cells use GABA as a gliotransmitter to modulate taste signals? Our pilot data suggest that Type I cells are key players in GABAergic circuits in taste buds. We will complete production of a unique transgenic mouse strain in which yellow fluorescent protein (YFP) is expressed only in Type I cells of taste buds. We will then use these and our other transgenic mice to identify the cell-type selective pattern of receptors and confocal Ca2+ imaging to analyze GABA-mediated responses in these cells types, especially with respect to the impact on taste-evoked responses. 3. Do Type I cells arise from local epithelium and what is their lifespan? Cells in taste buds have an estimated average lifespan of 10-14 days. Earlier studies did not confidently resolve taste cell types. We will employ a new technology for birth-dating cells to assess if the different taste cell types have different lifespans and lineages. Through this series of testable hypotheses and powerful new technologies focused on Type I taste bud cells, we will begin to address the larger, and decades-old question: why do chemosensory taste cells form communities (i.e. taste buds)? What signals are processed within taste buds and what role in taste reception does ongoing communication among the cells serve?

Public Health Relevance

Taste buds detect nutritive and potentially poisonous materials through the coordinated action of distinct types of cells housed in taste buds throughout the oral cavity. We will investigate how cells located in taste buds, but resembling glia, may influence the sensitivity of taste buds. Because the proteins responsible for regulation are in an accessible location, understanding these mechanisms introduces the possibility of pharmacological manipulation of aversive and appetitive taste sensations.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
5R01DC006308-08
Application #
8304284
Study Section
Special Emphasis Panel (ZRG1-IFCN-E (02))
Program Officer
Sullivan, Susan L
Project Start
2003-07-01
Project End
2015-08-31
Budget Start
2012-09-01
Budget End
2013-08-31
Support Year
8
Fiscal Year
2012
Total Cost
$314,721
Indirect Cost
$109,021
Name
University of Miami School of Medicine
Department
Physiology
Type
Schools of Medicine
DUNS #
052780918
City
Coral Gables
State
FL
Country
United States
Zip Code
33146
Roper, Stephen D; Chaudhari, Nirupa (2017) Taste buds: cells, signals and synapses. Nat Rev Neurosci 18:485-497
Dvoryanchikov, Gennady; Hernandez, Damian; Roebber, Jennifer K et al. (2017) Transcriptomes and neurotransmitter profiles of classes of gustatory and somatosensory neurons in the geniculate ganglion. Nat Commun 8:760
Goldstein, Bradley J; Goss, Garrett M; Choi, Rhea et al. (2016) Contribution of Polycomb group proteins to olfactory basal stem cell self-renewal in a novel c-KIT+ culture model and in vivo. Development 143:4394-4404
Goss, Garrett M; Chaudhari, Nirupa; Hare, Joshua M et al. (2016) Differentiation potential of individual olfactory c-Kit+ progenitors determined via multicolor lineage tracing. Dev Neurobiol 76:241-51
Dando, Robin; Pereira, Elizabeth; Kurian, Mani et al. (2015) A permeability barrier surrounds taste buds in lingual epithelia. Am J Physiol Cell Physiol 308:C21-32
Sinclair, Michael S; Perea-Martinez, Isabel; Abouyared, Marianne et al. (2015) Oxytocin decreases sweet taste sensitivity in mice. Physiol Behav 141:103-10
Roebber, Jennifer K; Izenwasser, Sari; Chaudhari, Nirupa (2015) Cocaine decreases saccharin preference without altering sweet taste sensitivity. Pharmacol Biochem Behav 133:18-24
Chaudhari, Nirupa (2014) Synaptic communication and signal processing among sensory cells in taste buds. J Physiol 592:3387-92
Perea-Martinez, Isabel; Nagai, Takatoshi; Chaudhari, Nirupa (2013) Functional cell types in taste buds have distinct longevities. PLoS One 8:e53399
Chaudhari, Nirupa (2013) Sweet umami: the twain shall meet. J Physiol 591:1597

Showing the most recent 10 out of 29 publications