RT Journal Article
SR Electronic
T1 GABA, Its Receptors, and GABAergic Inhibition in Mouse Taste Buds
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 5782
OP 5791
DO 10.1523/JNEUROSCI.5559-10.2011
VO 31
IS 15
A1 Gennady Dvoryanchikov
A1 Yijen A. Huang
A1 Rene Barro-Soria
A1 Nirupa Chaudhari
A1 Stephen D. Roper
YR 2011
UL http://www.jneurosci.org/content/31/15/5782.abstract
AB Taste buds consist of at least three principal cell types that have different functions in processing gustatory signals: glial-like (type I) cells, receptor (type II) cells, and presynaptic (type III) cells. Using a combination of Ca2+ imaging, single-cell reverse transcriptase-PCR and immunostaining, we show that GABA is an inhibitory transmitter in mouse taste buds, acting on GABAA and GABAB receptors to suppress transmitter (ATP) secretion from receptor cells during taste stimulation. Specifically, receptor cells express GABAA receptor subunits β2, δ, and π, as well as GABAB receptors. In contrast, presynaptic cells express the GABAA β3 subunit and only occasionally GABAB receptors. In keeping with the distinct expression pattern of GABA receptors in presynaptic cells, we detected no GABAergic suppression of transmitter release from presynaptic cells. We suggest that GABA may serve function(s) in taste buds in addition to synaptic inhibition. Finally, we also defined the source of GABA in taste buds: GABA is synthesized by GAD65 in type I taste cells as well as by GAD67 in presynaptic (type III) taste cells and is stored in both those two cell types. We conclude that GABA is an inhibitory transmitter released during taste stimulation and possibly also during growth and differentiation of taste buds.