抄録
Nucleus tractus solitarius (NTS) plays a major role in the regulation of cardiovascular, respiratory, gustatory, hepatic and swallowing functions. This nucleus receives primary afferent input from a wide variety of peripheral organs and tissues and is essential in integration of autonomic nervous system functions. Glutamate is one of the principal neurotransmitters of the afferents in the NTS. Indeed, it was well established that glutamate receptor exert a role in controlling the excitability of the NTS. Voltage-dependent calcium channels (VDCCs) serve as crucial mediators of membrane excitability and calcium-dependent functions such as neurotransmitter release, enzyme activity and gene expression. The modulation of VDCCs is believed to be an important means of regulating calcium entry and thus has a direct influence on many calcium-dependent processes. This study investigates the modulation of the VDCCs current (ICa) using patch-clamp recording methods. Application of (RS)-3,5-Dihydroxyphenylglycine (DHPG, Group one mGluR agonist) caused both inhibition and facilitation of ICa. In addition, application of L-(+)-2-amino-4-phosphonobutyric acid (AP-4, Group three mGluR agonist) caused facilitation of ICa. Neither (2S, 2'R, 3'R)-2-(2', 3'-dicarboxycyclopropyl)glycine (DCG, Group two mGluR agonist) nor (RS)-2-chloro-5-hydroxyphenylglycine (CHPG, mGluR5 agonist) modulated ICa. [Jpn J Physiol 54 Suppl:S141 (2004)]
