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Cell‐to‐cell communication in intact taste buds through ATP signalling from pannexin 1 gap junction hemichannels
Author(s) -
Dando Robin,
Roper Stephen D.
Publication year - 2009
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.2009.180083
Subject(s) - taste bud , pannexin , taste , microbiology and biotechnology , purinergic receptor , apyrase , gap junction , biology , cell type , secretion , connexin , chemistry , cell , intracellular , biochemistry , extracellular
Isolated taste cells, taste buds and strips of lingual tissue from taste papillae secrete ATP upon taste stimulation. Taste bud receptor (Type II) cells have been identified as the source of ATP secretion. Based on studies on isolated taste buds and single taste cells, we have postulated that ATP secreted from receptor cells via pannexin 1 hemichannels acts within the taste bud to excite neighbouring presynaptic (Type III) cells. This hypothesis, however, remains to be tested in intact tissues. In this report we used confocal Ca 2+ imaging and lingual slices containing intact taste buds to test the hypothesis of purinergic signalling between taste cells in a more integral preparation. Incubating lingual slices with apyrase reversibly blocked cell‐to‐cell communication between receptor cells and presynaptic cells, consistent with ATP being the transmitter. Inhibiting pannexin 1 gap junction hemichannels with CO 2 ‐saturated buffer or probenecid significantly reduced cell–cell signalling between receptor cells and presynaptic cells. In contrast, anandamide, a blocker of connexin gap junction channels, had no effect of cell‐to‐cell communication in taste buds. These findings are consistent with the model for peripheral signal processing via ATP and pannexin 1 hemichannels in mammalian taste buds.