5-羟色胺促进牛蛙初级传入神经元中γ-氨基丁酸诱导的去极化。

5-Hydroxytryptamine facilitates GABA-induced depolarization in bullfrog primary afferent neurons.

作者信息

Akasu T

机构信息

Department of Physiology, Kurume University School of Medicine, Japan.

出版信息

Neurosci Lett. 1988 Oct 17;92(3):270-4. doi: 10.1016/0304-3940(88)90601-5.

DOI:10.1016/0304-3940(88)90601-5

PMID:2849072

Abstract

Intracellular and voltage-clamp recordings were made from sensory neurons in bullfrog dorsal root ganglia (DRG). Bath-application of 5-hydroxytryptamine (5-HT, 10 microM to 1 mM) reversibly increased the amplitude of depolarizing responses to gamma-aminobutyric acid (GABA) and muscimol. 5-HT also increased the amplitude of chloride current activated by GABA. An analysis with dose-response curves revealed that 5-HT potentiated the maximum GABA current (Vmax), while it produced no significant change in the apparent dissociation constant (Km). It is suggested that 5-HT increases the sensitivity of the GABAA receptor, acting on an allosteric site for the receptor-ionophore complex.

摘要

从牛蛙背根神经节（DRG）的感觉神经元进行细胞内和电压钳记录。浴槽中应用5-羟色胺（5-HT，10微摩尔至1毫摩尔）可使对γ-氨基丁酸（GABA）和蝇蕈醇的去极化反应幅度可逆性增加。5-HT还增加了由GABA激活的氯离子电流幅度。剂量反应曲线分析显示，5-HT增强了最大GABA电流（Vmax），而对表观解离常数（Km）无显著影响。提示5-HT通过作用于GABAA受体-离子通道复合物的变构位点来增加该受体的敏感性。