急性弥散性不完全性脑缺血时大鼠海马及运动皮质脑电图和GABA能神经元的变化

CHANGES OF ELECTROENCEPHALOGRAM AND GABA ERGIC NEURONS OF HIPPOCAMPUS AND MOTOR CORTEX IN THE RAT DURING ACUTE DIFFUSE UNCOMPLETE CEREBRAL ISCHEMIA

用电生理及免疫细胞化学方法观察急性脑缺血大鼠海马及运动皮质的脑电图和其内ＧＡＢＡ能神经元的变化。结果表明：夹闭双侧颈总动脉１５ｍｉｎ后，海马及运动皮质的脑电波波幅变低、频率变慢、高幅θ波增多，有时呈短程阵发性出现。这些变化随着缺血的发展而更加明显，有时出现癫痫样棘波或棘慢波或阵发性尖波。缺血１ｈ后，脑电波有所恢复，但没有恢复到正常水平。免疫细胞化学染色结果：缺血３０ｍｉｎ后，海马及运动皮质内ＧＡＢＡ能神经元开始减少，２ｈ后明显减少。此时海马内约为对照组的６０％左右，表现最明显的部位为齿状回和ＣＡ１及ＣＡ３区。运动皮质内比对照组减少５０％左右。结果提示：急性弥散性不完全性脑缺血时，由于脑血供减少，导致抑制性ＧＡＢＡ能神经元数量减少，出现海马及运动皮质脑电图和行为明显改变，这些变化可能与脑缺血所致的机能障碍和临床表现有关。

Changes of electroencephalogram(EEG)and GABA ergic neurons of hippocampus and motor cortex in the rat during cerebral ischemia were observed by electrophysiological and immunocytochemical method. The resu1ts showed that 15 minutes after occlusion of biateral common carotid the amplitude of electroencephalogram in the hippocampus and motor cortex became lower,the frequency slowed and high-amplitude waves increased,sometimes appeared paroxismally.These changes become more obvious with the developing of cerebral ischemia. Sometimes the epileptiform spike waves,spike and slow waves or paroxysmal sharp waves appeared.An hour later the EEG was recovered,but not returned to normal level.The results ofimmunocvtochemistry showed that 30 minutes after occlusion the GABA ergic neurons of the hippocampus and motor cortex began to reduce and showed obvious after 2 hours.At this time,the number of GABAergic neurons in the hippocampus was approximately 60%of that in the control group with prominent reduction in the dentate gyrus,CA1 and CA3 ateas. Whereas,about 50%of that in control group appeared in the motor cortex. The above results suggested that during acute diffuse uncomplete cerebral ischemia,the reduction of blood supply of brain led to the loss of inhibitory GABA ergic neurons. Therefore,obvious changes of EEG in the hippocampus and motor cortex and behaviour disturbence occured.All these changes might relate to the functional obstacle and clinical manifestation in cerebral ischemia.