This proposal investigates synaptic transmitters in mammalian taste buds.
My Specific Aims i nclude identifying the principal transmitters released by mouse taste cells during gustatory stimulation and determining where these transmitters act. Transmitters that have been identified to date and shown to be released by taste cells include serotonin, ATP, and norepinephrine. However, there is strong evidence that there are others, including glutamate, acetylcholine, and certain peptides. To complete the Aims, we will use a biosensor technique we developed and optimized in the previous funding period. Our biosensors consist of genetically-engineered CHO cells that are very sensitive to specific transmitters. We will use functional Ca2+ imaging to measure taste-evoked activity in taste cells and biosensors. We will correlate our findings with immunostaining for the receptors, transporters, and biosynthetic enzymes of candidate transmitters to confirm their presence and action in taste buds. This approach will allow us to answer such questions as: what are the transmitters in taste buds? Are there different transmitters for different tastes? How do taste cells interact via these transmitters? The long-term goal of this project is to construct a diagram of synaptic interactions that take place in the taste bud during taste stimulation. Understanding these interactions may help explain how different tastes (sweet, sour, salty, bitter, umami) are discriminated.

Public Health Relevance

This project aims to study transmitters involved in taste reception. Identifying taste transmitters and their receptors may allow pharmacological interventions that enhance the quality of life, alter diet selection, combat obesity, reduce aversive tastes, or in the rare but debilitating condition of dysgeusia and ageusia, may suggest new therapies. Identifying taste transmitters may also help explain taste alterations that occur as side effects of certain drugs and which reduce patient compliance in taking their medications.

National Institute of Health (NIH)
National Institute on Deafness and Other Communication Disorders (NIDCD)
Research Project (R01)
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Study Section
Somatosensory and Chemosensory Systems Study Section (SCS)
Program Officer
Sullivan, Susan L
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University of Miami School of Medicine
Schools of Medicine
Coral Gables
United States
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Roper, Stephen D; Chaudhari, Nirupa (2017) Taste buds: cells, signals and synapses. Nat Rev Neurosci 18:485-497
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
Meredith, Tricia L; Corcoran, Alan; Roper, Stephen D (2015) Leptin's effect on taste bud calcium responses and transmitter secretion. Chem Senses 40:217-22
Roper, Stephen D (2015) The taste of table salt. Pflugers Arch 467:457-63
Roper, Stephen D (2014) Sensory end-organs: signal processing in the periphery: a symposium presented at the 2013 Annual Meeting of the Society for Neuroscience, San Diego, CA, USA. J Physiol 592:3383-5
Roper, Stephen D (2014) TRPs in taste and chemesthesis. Handb Exp Pharmacol 223:827-71
Roper, Stephen D (2013) Taste buds as peripheral chemosensory processors. Semin Cell Dev Biol 24:71-9
Roper, Stephen D (2013) Introduction to signal processing in peripheral sensory organs. Semin Cell Dev Biol 24:1-2
Huang, Yijen A; Grant, Jeff; Roper, Stephen (2012) Glutamate may be an efferent transmitter that elicits inhibition in mouse taste buds. PLoS One 7:e30662
Dando, Robin; Roper, Stephen D (2012) Acetylcholine is released from taste cells, enhancing taste signalling. J Physiol 590:3009-17

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