GABA, its receptors, and GABAergic inhibition in mouse taste buds.
GABA, its receptors, and GABAergic inhibition in mouse taste buds.
复制标题
GABA，其受体和小鼠味蕾中的GABA能抑制作用。
DOI：
10.1523/jneurosci.5559-10.2011
复制
发表时间：
2011-04-13
期刊：
影响因子：
--
通讯作者：
Roper SD
中科院分区：
文献类型：
--
作者：
Dvoryanchikov G;Huang YA;Barro-Soria R;Chaudhari N;Roper SD
味蕾至少由三种在处理味觉信号方面具有不同功能的主要细胞类型组成--胶质样I型细胞、受体(II型)细胞和突触前(III型)细胞。结合钙离子成像、单细胞逆转录聚合酶链式反应和免疫染色，我们发现γ-氨基丁酸是小鼠味蕾中的抑制性递质，作用于GABA-A和GABA-B受体，在味觉刺激过程中抑制受体细胞的递质分泌。具体地说，受体细胞表达GABA-A受体亚基β2、δ，π以及GABA-B受体。相反，突触前细胞表达β-A GABA3亚单位，偶尔表达GABAGABA-B受体。与突触前细胞不同的GABA受体表达模式一致，我们没有检测到GABA能抑制突触前细胞的递质释放。我们认为，GABA可能在味蕾中起作用(S)，而不是突触抑制。最后，我们还确定了味蕾中GABA的来源：GABA在I型味觉细胞中由GAD65合成，在突触前(III型)味觉细胞中由GAD67合成，并储存在这两种细胞中。我们的结论是，GABA在味觉刺激过程中释放，可能也在味蕾的生长和分化过程中释放。
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 RT-PCR, and immunostaining, we show that γ-amino butyric acid (GABA) is an inhibitory transmitter in mouse taste buds, acting on GABA-A and GABA-B receptors to suppress transmitter (ATP) secretion from Receptor cells during taste stimulation. Specifically, Receptor cells express GABA-A receptor subunits β2, δ, π, as well as GABA-B receptors. In contrast, Presynaptic cells express the GABA-Aβ3 subunit and only occasionally GABA-B 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 released during taste stimulation and possibly also during growth and differentiation of taste buds.