AN ANALYSIS OF SYNAPTIC TRANSMISSION MECHANISM FROM TASTE RECEPTOR CELL TO GUSTATORY NERVE

味觉感受器细胞至味觉神经突触传递机制分析

基本信息

批准号：
12671810
负责人：
MIYAMOTO Takenori
金额：
$ 1.98万
依托单位：
NAGASAKI UNIVERSITY GRADUATE SCHOOL OF BIOMEDICAL SCIENCES
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

项目摘要

Immunohistochemical studies have demonstrated that taste receptor cells containing serotonin exist in taste buds. In the previous studies, we detected serotonin secreted from the serosal side of the lingual epithelium in response to the repeated application of NaCl or citric acid to the mucosal side of the lingual epithelium using full-automatical perfusion/sampling device for epithelial tissue and HPLC. Therefore, we attempted to detect serotonin secreted from a single taste bud in response to the application of taste stimuli to the taste pore using localized stimulation procedure and carbon fiber electrodes. However, we were unable to detect any monoamines. We attempted to immunohistochemically detect localization of several subtypes of glutamatergic receptor molecules in the taste buds of the fungiform papilla. One of the metabotropic glutamatergic receptors, mGluR4 was detected in the taste bud cells, but not in the gustatory nerve terminal of the afferent synapse. Taken together w … More ith electrophysiological data, mGluR4 in the taste bud cells possibly play an inhibitory role for transduction mechanism of umami. These results suggest mat substances other than glutamate and monoamines mediate the transmission from taste receptor cells to gustatory nerves. Therefore, we performed a bioassay using vallate papilla (VP)/von Ebner's gland (VEG) complex, where several receptor molecules are expressed on the acinar cells. The results indicated that localized bitter stimuli to the cleft of isolated vallate papilla suppressed voltage-gated K^+ currents of acinar cells, whereas sour stimuli induced inward current responses in acinar cells with slow time course, suggesting that these actions of taste stimuli are due to paracrine effect of transmitters released from taste bud cells. These findings also suggest that transmitter released by bitter stimulus is different from that by sour stimulus, and receptor molecules for these multiple transmitters were expressed on acinar cells of VEG. Less

免疫组织化学研究表明，味蕾中存在含有血清素的味觉受体细胞。在先前的研究中，我们使用全自动灌注/采样装置在上皮组织和HPLC中反复应用NaCl或柠檬酸在语言上皮的粘膜侧的重复应用，从舌上上皮的血清侧分泌的血清素。因此，我们尝试使用局部刺激程序和碳纤维电极来检测从单个味蕾分泌的血清素，以响应味觉刺激的应用到味道孔。但是，我们无法检测到任何单胺。我们试图通过免疫组织化学检测谷氨酸能受体分子的几种亚型在真菌乳头的味蕾中的定位。在味蕾细胞中检测到了代谢性谷氨酸能受体之一，但在传入突触的味道神经末端未检测到。总而言之……味蕾细胞中的更多ITH电生理数据，MGLUR4可能对乌玛米传输机制起抑制作用。这些结果表明，除了谷氨酸和单胺以外，其他MAT物质的中位数是从味觉受体细胞到味觉神经的传播。因此，我们使用Vallate Papilla（VP）/Von Ebner的腺体（VEG）复合物进行了生物测定，其中几种受体分子在腺泡细胞上表达。结果表明，局部的苦刺刺激刺激了腺泡细胞的电压门控的K^+电流，而酸刺激诱导了缓慢的时间过程中的腺泡细胞中的内向反应，这表明这些味道刺激的作用是由于从味蕾中释放出寄生虫的副分泌作用而引起的。这些发现还表明，苦刺释放的发射器与酸刺激的发射器不同，这些多个发射器的受体分子在VEG的腺泡细胞上表达。较少的