一氧化氮对谷氨酸诱发的大鼠海马脑片CA1区神经元活动的抑制
薛保建, 王志安, 何瑞荣
河北医科大学基础医学研究所生理室
摘要
用细胞外记录单位放电技术,在大鼠海马脑片上观察了L-精氨酸(L-arg)、N-硝基L-精氨酸(L-NNA)及SIN-1对谷氨酸(glutamate,Glu)诱发的CA1区神经元放电的影响。旨在了解L-精氨酸:NO通路在谷氨酸诱发的海马放电中的作用及其可能的机制。结果如下:(1)用Gln(0.5mmol/L)灌流海马脑片1min,12个放电单位放电频率明显增加,表现为癫痛样放电;(2)预先用含Glu(0.5mmol/L)的人工脑脊液(ACSF)灌流脑片,继而应用L-arg(10mmol/L)灌流海马脑片2min,10个放电单位放电频率均明显降低;(3)预先用含Gln(0.5mmol/L)的ACSF灌流脑片,再用一氧化氮供体SIN-1(5mmol/L)灌流海马脑片1min,12个放电单位放电频率明显减少;(4)在预先用含Glu(0.5mmol/L)的ACSF灌流脑片基础上,应用L-NNA(0.15mmol/L)灌流脑片2min,12个放电单位放电频率均明显增加,并有一些神经元最终突然停止放电。综合上述结果,似可以认为,Glu与海马神经元上的NMDA受体结合后,不仅引发神经元放电明显增加,而且激活L-arg:NO通路而生成NO,再通过负反馈机制对神经元起保护作用。
MA Yong-Jie
2College of Information Engineering, Taishan Medical University, Taian 271016, China
Abstract
Using extracellular recording technique,the effects of L-arginine(L-arg),SIN-1 and N-nitro-Larginine(L-NNA)on glutamate-induced dischargn of neamns in CA1 area of hippocapal slices were examined to define the role of L-arg:NO pathway in glutamate induced discharge of hippocaampal neurons and its possible underlying mechanism.The results obtrined are as follow. (1)In response to the application of glutamae(0.5 mmol/L)into the superfusate for l min,the discharge rate of 12 neurons was increased markedly in an epileptiform pattern.(2)The increased discharge induced by glutamae (0.5mmol/L)in 10 neurons was suppressed significantly by appication of L-arg(10 mmol/L)into the superfusate for 2 min.(3)The glutamate-induced increase of discharge in 12 neurons was decreased maredly by superfusing the brain slice with NO donor SIN 1(5 mmol/L)for 1 min.
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引用本文:
薛保建, 王志安, 何瑞荣. 一氧化氮对谷氨酸诱发的大鼠海马脑片CA1区神经元活动的抑制 [J]. 生理学报 1998; 50 (1): .
MA Yong-Jie. . Acta Physiol Sin 1998; 50 (1): (in Chinese with English abstract).