M受体亚型阻断剂对大鼠尾核痛抑制神经元放电的影响  

Effects of M-receptor subtype antagonists on pain-inhibition neurons in caudate nucleus

作　　者：姚坤[1] 李玉荣[1] 王腾[1] 曲丽辉[1] 田华[1] 金宏波[1] 王伟[1] 刘松涛[1] 

机构地区：[1]哈尔滨医科大学生理学教研室,黑龙江哈尔滨150081

出　　处：《哈尔滨医科大学学报》2007年第4期340-343,共4页Journal of Harbin Medical University

摘　　要：目的研究侧脑室注射M1、M3、M4受体亚型阻断剂对乙酰胆碱(ACh)引起的大鼠尾核痛抑制神经元(PIN)电活动的影响。方法以电脉冲刺激左侧坐骨神经作为伤害性刺激,用玻璃微电极细胞外记录大鼠尾核PIN放电的变化,观察侧脑室注射不同M受体亚型阻断剂对其影响。结果①脑室注射ACh(20μg/10μL)加强了尾核痛抑制神经元的电活动;②M1受体阻断剂哌仑西平(10μg/10μL)可部分阻断ACh的作用。而M3受体阻断剂4-DAMP和M4受体阻断剂托品酰胺对ACh的镇痛效应无明显作用。结论乙酰胆碱在尾核中起镇痛作用,其镇痛机制主要涉及M1受体。Objective To study the effects of acetylcholine （ACh） on the electric activities of pain-inhibition neurons （PIN） in caudate nucleus in one side of rat brain after intracerebroventricular （i. c. v. ） injections of antagonists for muscarinic receptor subtype 1 （ M1 ）, 3 （ M3 ）, and 4 （ M4 ）. Methods Trains of the electric impulses applied to the left sciatic nerve were used as noxious stimulus, the discharge of pain-inhibition neurons was led out by extracellular recording method with the glass microelectrode in one side of rat caudate nucleus. The influence of i. c. v. injection of muscarinic receptor subtype antagonists on the noxious stimulation-evoked activities of PIN in caudate nucleus were observed. Results ①I. c. v. injection of ACh （20μg/10μL） resulted in an excitation of evoked response of PIN; ②The excitatory effect on the electric discharges of PIN of ACh was partly blocked by i. c. v. administration of M1 receptor antagonist pirenzepine at the dose of 10μg/10μL. M3 receptor antagonist 4-DAMP and M4 receptor antagonist tropicamide could not block the effect of ACh. Conclusion ACh plays an inhibitory role in regulating pain. M1 receptor was mainly involved in this analgesia mechanism.

关 键 词：乙酰胆碱 尾核 痛抑制神经元 脑室注射 受体 

分 类 号：R338.8[医药卫生—人体生理学]