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乙酰胆碱对离体大鼠延髓头端腹外侧区神经元自发放电的影响

储祥平 李鹏 徐宁善

上海医科大学生理学教研室. 上海 200032

摘要

在89张Sprague－Dawley大鼠延髓脑片上，用玻离微电极记录到165个延髓头端腹外侧区(RVLM)神经元的自发放电，其放电形式有三种：规则型(102个，61.8％)；不规则型(40个，24.2％)；静息型(23个，14％)。乙酰胆碱(ACh，0．1，0.3，1.0，3.0μmol/L，1～3min)对自发放电有兴奋、抑制、双相和无影响四种效应，各占所测试神经元数的41.8％，20％，3％和35.2％。兴奋效应呈剂量一反应关系。此外，观察了49例ACh对RVLM神经元的效应(兴奋效应29例，抑制效应20例)，这些效应大部分被阿托品所阻断(n＝42)；ACh的兴奋效应(n=14)大部分可被胆碱能M1受体特异性拮抗剂吡卓酮(PZ，10，30nmol/L)所拮抗(n=9)，而不被M2受体特异性拮抗剂聚亚甲基四胺(MT)和AFDX－116所拮抗；ACh的抑制效应(n=10)大部分可被MT(10，30nmol/L)所拮抗(n=7)；而这种抑制效应(n=9)也可被AFDX-116(10，30nmol/L)所拮抗(n=6)，但是，ACh的这种抑制效应不能被PZ阻断。

关键词： 乙酰胆碱; 延髓脑片; 延髓头端腹外侧区; 自发单位放电; M受体亚型

Effects of ACh on the electric activity of rostral ventrolateral medullary neurons of rat in vitro

Chu Xiangping

Department of Physiology, Shanghai Medical University. Shanghai 200032, China

Abstract

Extracellular single-unit discharges were obtained from l65 spontaneously active neurons within the region of the rostral ventrolateral medulla (RVLM) by glass microelectrode from 89 brain slices of the SpragUe-Dawley rats. The units could be divided into three types: regular (61.8%), irregular (24.2%) and silent (14%). Acetylcholine (ACh, 0.1, 0.3 #mu#mol/L) showed four kinds of effects on spontaneous discharges of RVLM neurons: excitatory, inhibitory, biphasic and non-responsive, counting respectively 41.8%, 20%, 3% and 35.2% of the neurons tested. The excitatory effect of ACh was dose-dependent. The effects, either excitatory or inhibitory,of ACh (n=49) were mostly blocked by atropine (0.3 #mu#mol/L, n=42). The excitatory effect of ACh (n=14) could be blocked mainly by selective antagonist of M_(1) receptor,pirenzepine (PZ, 30 nmol/L, n=9), but not by selective antagonist of M_(2) receptor,methoctramine (MT) and AFDX-116.

Key words: Acetylcholine;Brain slices of medulla;Rostral ventrolateral medulla;Spontaneous singleunit discharge;Subtype of muscarinic receptor

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引用本文：

储祥平 李鹏 徐宁善. 乙酰胆碱对离体大鼠延髓头端腹外侧区神经元自发放电的影响[J]. 生理学报 1997; 49 (6): .

Chu Xiangping. Effects of ACh on the electric activity of rostral ventrolateral medullary neurons of rat in vitro. Acta Physiol Sin 1997; 49 (6): (in Chinese with English abstract).