Document Detail


Separate populations of receptor cells and presynaptic cells in mouse taste buds.
MedLine Citation:
PMID:  16611813     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Taste buds are aggregates of 50-100 cells, only a fraction of which express genes for taste receptors and intracellular signaling proteins. We combined functional calcium imaging with single-cell molecular profiling to demonstrate the existence of two distinct cell types in mouse taste buds. Calcium imaging revealed that isolated taste cells responded with a transient elevation of cytoplasmic Ca2+ to either tastants or depolarization with KCl, but never both. Using single-cell reverse transcription (RT)-PCR, we show that individual taste cells express either phospholipase C beta2 (PLCbeta2) (an essential taste transduction effector) or synaptosomal-associated protein 25 (SNAP25) (a key component of calcium-triggered transmitter exocytosis). The two functional classes revealed by calcium imaging mapped onto the two gene expression classes determined by single-cell RT-PCR. Specifically, cells responding to tastants expressed PLCbeta2, whereas cells responding to KCl depolarization expressed SNAP25. We demonstrate this by two methods: first, through sequential calcium imaging and single-cell RT-PCR; second, by performing calcium imaging on taste buds in slices from transgenic mice in which PLCbeta2-expressing taste cells are labeled with green fluorescent protein. To evaluate the significance of the SNAP25-expressing cells, we used RNA amplification from single cells, followed by RT-PCR. We show that SNAP25-positive cells also express typical presynaptic proteins, including a voltage-gated calcium channel (alpha1A), neural cell adhesion molecule, synapsin-II, and the neurotransmitter-synthesizing enzymes glutamic acid decarboxylase and aromatic amino acid decarboxylase. No synaptic markers were detected in PLCbeta2 cells by either amplified RNA profiling or by immunocytochemistry. These data demonstrate the existence of at least two molecularly distinct functional classes of taste cells: receptor cells and synapse-forming cells.
Authors:
Richard A DeFazio; Gennady Dvoryanchikov; Yutaka Maruyama; Joung Woul Kim; Elizabeth Pereira; Stephen D Roper; Nirupa Chaudhari
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Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural    
Journal Detail:
Title:  The Journal of neuroscience : the official journal of the Society for Neuroscience     Volume:  26     ISSN:  1529-2401     ISO Abbreviation:  J. Neurosci.     Publication Date:  2006 Apr 
Date Detail:
Created Date:  2006-04-13     Completed Date:  2006-05-02     Revised Date:  2013-09-05    
Medline Journal Info:
Nlm Unique ID:  8102140     Medline TA:  J Neurosci     Country:  United States    
Other Details:
Languages:  eng     Pagination:  3971-80     Citation Subset:  IM    
Affiliation:
Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, Florida 33136, USA.
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MeSH Terms
Descriptor/Qualifier:
Animals
Calcium / physiology
Mice
Mice, Inbred C57BL
Models, Animal
Potassium / pharmacology
Potassium Chloride / pharmacology
Presynaptic Terminals / drug effects,  physiology*
Reverse Transcriptase Polymerase Chain Reaction
Sensory Receptor Cells / physiology
Sodium Chloride / pharmacology
Taste Buds / physiology*
Grant Support
ID/Acronym/Agency:
1R01 DC06308/DC/NIDCD NIH HHS; 1R21 DC05500/DC/NIDCD NIH HHS; 2R01 DC00374/DC/NIDCD NIH HHS; R01 DC000374/DC/NIDCD NIH HHS; R01 DC006308/DC/NIDCD NIH HHS; R21 DC005500/DC/NIDCD NIH HHS
Chemical
Reg. No./Substance:
7440-09-7/Potassium; 7440-70-2/Calcium; 7447-40-7/Potassium Chloride; 7647-14-5/Sodium Chloride
Comments/Corrections

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