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刺激大鼠中脑导水管周围灰质诱发的脊髓背根电位及其传出途径的分析

张爱玲, 程珍凤

西安医科大学生理教研室. 北京 2619信箱；中国康复研究中心生理室

摘要

电刺激大鼠中脑导水管周围灰质(PAG),在腰5[L_(5)]背根可记录到—稳定的负性背根电位(DRP),简称 PAG-DRP。PAG-DRP 具有空间和时间总和性质,沿背根作电紧张性扩布,且能被 GABA 能拮抗剂印防己毒素(Picrotoxin)所抑制。电解损毁中缝大核(NRM)对刺激背侧 PAG 诱发的 PAG-DRP 无明显影响,而可使刺激腹侧 PAG 诱发的 PAG-DRP电位幅值降低40%左右。结果表明,PAG 下行抑制作用中有突触前抑制参与;NRM 参与腹侧 PAG-DRP 的产生,背侧 PAG-DRP 则可能由 NRM 以外的其他核团中继。

关键词： 中脑导水管周围灰质; 中缝大核; 脊髓背根电位; 突触前抑制

Dorsal root potential evoked by stimulation of periaqueductal gray and its efferent pathway analysis in rats

Zhang Ailing, Cheng Zhenfeng

Department of Physiology, Xi'an Medical University. Xi'an, China

Abstract

When periaqueductal gray (PAG) was stimulated with concentric electrodes,
a steady negative potential called PAG-DRP was recorded from L_(5) dorsal root.
PAG-DRP with properties of spatial and temporal summation propagates decre-
mentally along the dorsal root and is inhibited by picrotoxin. Lesions of NRM
had no effect on the PAG-DRP evoked by stimulation of dorsal PAG, but showed
obvious reduction up to about 40% on the PAG-DRP evoked stimulation of ven-
tral PAG. It is suggested that the descending inhibition of PAG includes some
presynaptic inhibition and that the ventral PAG-DRP is relayed partly via NRM
while the dorsal PAG-DRP is not associated with NRM.

Key words: Periaqueductal gray;Nucleus raphe magnus;Spinal dorsal root potential;Presyasptic inhibition

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引用本文：

张爱玲, 程珍凤. 刺激大鼠中脑导水管周围灰质诱发的脊髓背根电位及其传出途径的分析[J]. 生理学报 1990; 42 (3): .

Zhang Ailing, Cheng Zhenfeng. Dorsal root potential evoked by stimulation of periaqueductal gray and its efferent pathway analysis in rats. Acta Physiol Sin 1990; 42 (3): (in Chinese with English abstract).