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5-HT对弓状核神经元的直接兴奋作用和通过GABA能局部神经元实现的抑制作用

康玉明, 陈健勇, 欧阳玮, 乔健天

山西医科大学神经生物学研究室.山西,太原 030001

摘要

用大鼠离体灌流脑片的细胞外单一神经元电生理记录技术,观察了5-HT对弓状核神经元自发放电的影响。结果表明:(1)在随机选取的149个神经元中,有33个(22.2％)可被5-HT兴奋,82个(55.0％)被抑制,其余34个(22.8％)出现双相反应或不出现反应;(2)用低Ca~(2+)-高Mg~(2+)人工脑脊液替换正常人工脑脊液后,5-HT引起的兴奋效应仍可出现,但5-HT引起的抑制效应不再出现;(3)5-HT受体的非选择性拮抗剂cyproheptadine对5-HT引起的兴奋或抑制都有阻断作用;(4)用GABA受体拮抗剂bicuculline(Bic)可以阻断5-HT引起的抑制作用。

关键词： 弓状核; 神经元; 5羟色胺(5-HT); 赛庚啶; 荷包牡丹碱; 脑片

Serotonin excites arcuate neurons directly but inhibits them through intercalated GABAergic neurons

Kang Yuming, Chen Jianyong, Ouyang Wei, Qiao Jiantian

Department of Neurobiology,Shanxi Medical University.Taiyuan 030001,Shanxi

Abstract

Effects of serotonin (5-HT) on spontaneous discharges of single hypothalamic arcuate neurons were observed in rat brain slices by extracellular recordings. The results showed that (1) of 149 neurons selected randomly and tested for 5-HT application, 33 (22.2%) were excited, 82 (55.0%) were inhibited, and 34 (22.8%) showed biphasic responses or failed to respond; (2) substitution of low Ca~(2+)-high Mg~(2+) artificial cerebrospinal fluid (aCSF) for normal aCSF abolished the 5-HT-induced inhibitory effect but failed to affect the 5-HT-induced excitatory effect; (3)cyproheptadine, a non-selective 5-HT receptor antagonist, could block either the 5-HT-induced excitatory or inhibitory effects in all neurons tested; and (4) bicuculline, a GABA_(A)-receptor antagonist, blocked the 5-HT0induced inhibitory effect.

Key words: Arcuate nucleus;Neurons;Serotonin;Cyproheptadine;Bicuculline;Brain slice

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引用本文：

康玉明, 陈健勇, 欧阳玮, 乔健天. 5-HT对弓状核神经元的直接兴奋作用和通过GABA能局部神经元实现的抑制作用[J]. 生理学报 2002; 54 (3): .

Kang Yuming, Chen Jianyong, Ouyang Wei, Qiao Jiantian. Serotonin excites arcuate neurons directly but inhibits them through intercalated GABAergic neurons. Acta Physiol Sin 2002; 54 (3): (in Chinese with English abstract).