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谷氨酸及NMDA受体拮抗剂MK-801对大鼠伏核痛兴奋神经元电活动的影响

张秀娟, 徐满英, 吕宁

广东医学院生理教研室.广东，湛江 524023；哈尔滨医科大学生理教研室.黑龙江，哈尔滨 150086

摘要

该文研究了谷氨酸(glutamic acid, Glu)及其NMDA受体拮抗剂5-甲基二氢丙环庚烯亚胺马来酸（MK-801）对大鼠伏核(NAc)痛兴奋神经元(PEN)痛诱发反应的影响。电刺激坐骨神经作为伤害性刺激，用玻璃微电极记录NAc的PEN放电，观察脑室内注射Glu和NAc内注射MK-801对大鼠NAc中PEN伤害性诱发活动的影响。结果显示，伤害性刺激可使NAc的PEN电活动增强；脑室内注射Glu（10 nmol/10#mu#l）可使NAc的PEN伤害性诱发放电频率增加；NAc内注射MK-801（1.0 nmol/0.5#mu#l）可阻断这种作用；MK-801本身也可部分抑制PEN伤害性诱发反应。上述实验结果表明，Glu对PEN伤害性反应的易化作用是通过NMDA受体介导的。Glu和NMDA受体参与NAc伤害性信息传递的调制。

关键词： 谷氨酸; MK-801; 伏核; 痛兴奋神经元; 电活动

Influence of glutamate and NMDA-receptor antagonist MK-801 on the electric activities of pain-excitation neurons in the nucleus accumbens of rats

Zhang Xiujuan, Xu Manying, Lv Ning

Department of Physiology, Guangdong Medical College.Zhanjiang 524023,Guangdong；China

Abstract

The experiment explored the influence of glutamic acid (Glu) and the NMDA-receptor antagonist dizocilpine maleate (MK-801) on the pain-evoked responses of pain-excitation neurons (PEN) in the nucleus accumbens (NAc) of rats. The trains of electric impulses applied to the sciatic nerve were used as noxious stimulation. The discharges of PEN in NAc were recorded by glass microelectrode. We observed the influence of intracerebroventricular (icv) injection of Glu and microinjection of MK-801 into the NAc on the noxious stimulation-evoked activities of PEN in NAc. The results showed that the noxious stimulation potentiated the electric activities of PEN in NAc. Intracerebroventricular injection of Glu（10 nmol/10#mu#l） increased the frequency of the discharge of PEN evoked by the noxious stimulation in NAc, the Glu-induced response was blocked by the injection of MK-801（1.0 nmol/0.5#mu#l）into NAc. MK-801 partly inhibited the response of PEN upon the noxious stimulation. It is therefore suggested that the facilitatory effect of Glu on PEN response in NAc to the noxious stimulation were mediated by NMDA receptors, and that Glu and NMDA receptors are involved in the modulation of nociceptive information transmission in the NAc.

Key words: Glutamic acid;MK-801;Nucleus accumbens;Pain-excitation neurons;Electric activity

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引用本文：

张秀娟, 徐满英, 吕宁. 谷氨酸及NMDA受体拮抗剂MK-801对大鼠伏核痛兴奋神经元电活动的影响[J]. 生理学报 2005; 57 (1): .

Zhang Xiujuan, Xu Manying, Lv Ning. Influence of glutamate and NMDA-receptor antagonist MK-801 on the electric activities of pain-excitation neurons in the nucleus accumbens of rats . Acta Physiol Sin 2005; 57 (1): (in Chinese with English abstract).