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L-谷氨酸和卡巴胆碱对中脑腹侧被盖区多巴胺能神经元簇放电的影响

王姗姗, 魏春玲, 刘志强, 任维^*

陕西师范大学生命科学学院，西安 710062

摘要

中脑腹侧被盖区(ventral tegmental area, VTA)多巴胺能神经元的簇放电会导致其突触末梢多巴胺释放量瞬时大量增加，已被公认是编码奖赏效应的功能相关信号，但诱发多巴胺能神经元产生簇放电的神经调节的具体机制尚不完全清楚。为深入理解诱发VTA多巴胺能神经元产生簇放电介导奖赏信号的递质机制和不同脑区间的协同作用，本实验利用大鼠离体脑片，研究了胆碱能受体激动剂卡巴胆碱单独灌流，兴奋性谷氨酸能受体激动剂L-谷氨酸单独脉冲式给药及二者同时作用时VTA多巴胺能神经元簇放电的产生。结果显示，在离体脑片，卡巴胆碱(10 μmol/L)持续灌流或L-谷氨酸(3 mmol/L)脉冲式给药均能够诱发多巴胺能神经元产生簇放电。在二者单独作用不能诱发簇放电的神经元，卡巴胆碱和谷氨酸联合用药则可以诱发出簇放电。这些结果提示，卡巴胆碱和L-谷氨酸在诱发多巴胺能神经元簇放电的过程中具有协同作用。

关键词： 中脑边缘多巴胺系统; 簇放电; L-谷氨酸; 卡巴胆碱; 协同作用

分类号：Q424

[The influence of L-glutamate and carbachol on burst firing of dopaminergic neurons in ventral tegmental area.] [Article in Chinese]

WANG Shan-Shan, WEI Chun-Ling, Liu Zhi-Qiang, REN Wei^*

College of Life Science, Shaanxi Normal University, Xi’an 710062, China

Abstract

Burst firing of dopaminergic neurons in ventral tegmental area (VTA) induces a large transient increase in synaptic dopamine (DA) release and thus is considered the reward-related signal. But the mechanisms of burst generation of dopaminergic neuron still remain unclear. This experiment investigated the burst firing of VTA dopaminergic neurons in rat midbrain slices perfused with carbachol and L-glutamate individually or simultaneously to understand the neurotransmitter mechanism underlying burst generation. The results showed that bath application of carbachol (10 μmol/L) and pulse application of L-glutamate (3 mmol/L) both induced burst firing in dopaminergic neuron. Co-application of carbachol and L-glutamate induced burst firing in VTA dopaminergic cells which couldn’t be induced to burst by the two chemicals separately. The result indicates that carbachol and L-glutamate co-regulate burst firing of dopaminergic neuron.

Key words: mesolimbic dopamine system; burst firing; L-glutamate; carbachol; synergistic action

收稿日期：2010-11-05　　录用日期：2010-12-27

通讯作者：任维　　E-mail: renwei1964@vip.sina.com

引用本文：

王姗姗, 魏春玲, 刘志强, 任维. L-谷氨酸和卡巴胆碱对中脑腹侧被盖区多巴胺能神经元簇放电的影响[J]. 生理学报 2011; 63 (1): 25-30.

WANG Shan-Shan, WEI Chun-Ling, Liu Zhi-Qiang, REN Wei. [The influence of L-glutamate and carbachol on burst firing of dopaminergic neurons in ventral tegmental area.] [Article in Chinese]. Acta Physiol Sin 2011; 63 (1): 25-30 (in Chinese with English abstract).