Zhang W, Fang J Z, Wang S, Tang Y H
Department of Physiology, Bethame University of Medical Sciences, Changeham.
Sheng Li Xue Bao. 1993 Apr;45(2):190-5.
L-glutamic acid, bicuculline (a GABA receptor antagonist), lidocaine and GABA were injected into entopeduncular and habenular nuclei respectively in rats. Pain threshold was measured by the latency of avoidance response (tail-flick) elicited by radiant heat exposure before and after intracerebral injection. Microinjection of different concentration of L-glutamic acid (25 nmol/L.0.5 microliter-1, 50 nmol/L.0.5 microliter-1, 100 nmol/L.0.5 microliter-1) into bilateral entopeduncular nuclei resulted in increases of pain threshold in a dose-dependent manner. Similar increase of pain threshold could also be observed by microinjection of 200 nmol/L GABA.0.5 microliter-1 into bilateral habenular nuclei. Both the effect of GABA and that of glutamate, could be antagonized by 0.2% bicuculline. The results mentioned above indicate that GABAergic fibers are involved in the analgesic effect of entopeduncular-habenular complex.
分别将L-谷氨酸、荷包牡丹碱（一种GABA受体拮抗剂）、利多卡因和GABA注入大鼠的内侧缰核和缰核。在脑内注射前后，通过辐射热暴露引发的回避反应（甩尾）潜伏期来测量痛阈。向双侧内侧缰核微量注射不同浓度的L-谷氨酸（25 nmol/L.0.5微升-1、50 nmol/L.0.5微升-1、100 nmol/L.0.5微升-1），痛阈呈剂量依赖性增加。向双侧缰核微量注射200 nmol/L GABA.0.5微升-1也可观察到类似的痛阈升高。GABA和谷氨酸的作用均可被0.2%的荷包牡丹碱拮抗。上述结果表明，GABA能纤维参与了内侧缰核-缰核复合体的镇痛作用。
