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乙酞胆碱对培养大鼠皮层神经元兴奋性及抑制性突触电流的相反作用

刘青松, 何湘平, 刘传绩

(军事医学科学院毒物药物研究所，北京100850)

摘要

在分散培养的新生大鼠皮层神经元标本上，用全细胞电压箱技术分析了自发兴奋性及抑制性突触后电流(EPSC/IPSC)的性质并观察了乙酚胆碱(ACh)对它们的影响。EPSC与IPSC可分别被non-NMDA谷氨酸受体拮抗剂DNQX及GABA、受体拮抗剂bicuculline所取消，说明它们分别由这两种受体所介导。ACh在低浓度1 umol/L时减低IPSC发生频率，但不改变其幅度分布;高浓度ACh (10--100 pmol/L)增加EPSC的频率，也不改变其幅度分布。ACh的效应可为M受体拮剂阿托品所取消，但它对外源性谷氨酸及丫氨基丁酸引起的全细胞电流无显著影响。以上结果表明，皮层神经元可通过维持不同ACh水平来实现对其兴奋性及突触传递效率的精细调节。这一作用可能是通过作用于M受体，影响突触前递质释放来实现的。

关键词： 皮层神经元; 细胞培养; 乙酞胆碱; 突触传递; 膜片籍

OPPOSITE ACTIONS OF ACh ON EXCITATORY AND INHIBITORY SYNAPTIC TRANSMISSION IN CULTURED RAT CORTICAL NEURONS

LIU QING-SONG, HE XIANG-P工NG, LIU CHURN-GUI

InstdW of Toxicology and Pharnuxcology，Academy of Military Medical Sciences, Beijing 100850)

Abstract

Effect of ACh on spontaneous EPSC and IPSC in cultured postnatal rat cortical neurons was studied using whole-cell voltage-clamp technique. EPSC was blocked by a non-NMDA glutamate receptor antagonist DNQX，while IPSC was blocked by a GABA receptor antagonist bicuculline. When ACh(10一100 }tmol/L) was applied by puff pipettes to the cells recorded，the frequency of EPSC was enhanced greatly，but the amplitude distribution was not changed significantly. However，the frequency of IP SC was attenuated by ACh even at a quite low concentration(1 4mol/L).The effect of ACh on EPSC and IPSC could be blocked by M type ACh receptor antagonist atropine(1 }imol/L).ACh had no significant effect on whole-cell currents actived by glutamate, and GABA. The above results provide evidence that ACh has opposite effects on
excitatory and inhibitory synaptic transmission in rat cortex by acting at presynaptic sites. It is also suggested that ACh plays an important role in the maintenance of excitability of cortical neurons.

Key words: :cell culture;cortical neuron;;;

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引用本文：

刘青松, 何湘平, 刘传绩. 乙酞胆碱对培养大鼠皮层神经元兴奋性及抑制性突触电流的相反作用[J]. 生理学报 1996; 48 (4): .

LIU QING-SONG, HE XIANG-P工NG, LIU CHURN-GUI. OPPOSITE ACTIONS OF ACh ON EXCITATORY AND INHIBITORY SYNAPTIC TRANSMISSION IN CULTURED RAT CORTICAL NEURONS. Acta Physiol Sin 1996; 48 (4): (in Chinese with English abstract).