脑室注射γ—氨基丁酸对大鼠尾核痛反应神经元放电的影响

本文在32只大鼠上,用玻璃微电极引导神经元放电,观察了脑室注射γ-氨基丁酸(GABA)后,尾核痛反应神经元电活动的规律和印防已毒素(picrotoxin,PIX)对GABA的阻断效应。研究所见:当脑内GABA含量增加时,尾核痛兴奋神经元(pain excitation neurons,PEN)电活动受到抑制,表现为痛诱发放电频率下降,潜伏期延长;痛抑制神经元(pain inhibition neurons,PIN)电活动加强,表现为抑制时程缩短,痛诱发放电频率增加。PIX可阻断这种效应。综上表明,GABA通过同时影响尾核PEN和PIN的电活动而产生镇痛效应。

Effect of Intraventricular Injection of GABA on the Discharge of Pain Response Neurons in Rat Caudate Nuclei

This experiment was performed with two microelectrodes to simultaneously record the neuronal discharges of the pain excitation neurons (PEN) and the pain inhibition neurons (PIN) in the head of caudate nucleus in 32 Wistar rats. The effects of the intraventricular injection of GABA on the neuronal discharges as well as the block effect of picrotoxin( PIX) in caudate nucleus were studied.It was found that as the concentration of GABA increased, the electric activities of PEN was inhibited as shown by decreasing the frequency of the evoked discharges and prolonging the latency. In the contrast, the electric activities of PIN were exaggerated, showing shortening the inhibitory duration and increasing the frequency of the evoked discharges. These effects were antagonized by PIX.The results suggest that GABA may produce analgesic effects by simultaneously modulating the bio-electricity of the PEN and PIN in caudate nucleus.