Nishikawa Y, Takahashi T, Ogawa K
Department of Pathology, Asahikawa Medical College, Japan.
Mol Chem Neuropathol. 1994 May;22(1):25-41. doi: 10.1007/BF03160092.
The redistribution of glutamate and GABA in postischemic brains was examined immunocytochemically using the gerbil model of unilateral 1 h cerebral ischemia. In the cerebral neocortex, the majority of neurons underwent recovery processes after 5 h of recirculation, while neurons in the hippocampus were irreversibly damaged. Glutamate-like immunoreactivity (LI) was highly increased in the degenerating hippocampal CA3 pyramidal cells after recirculation, while in the neocortex and the hippocampal CA1 sector, the pyramidal cells showed only slightly increased glutamate-LI. GABA-LI-positive punctae in the neuropil, corresponding to neuronal processes of GABAergic neurons, were accentuated after recirculation both in the cerebral neocortex and the hippocampus. Although the astrocytes on the nonischemic side showed neither glutamate-LI nor GABA-LI, the swollen astrocytes and their foot processes, which were observed after recirculation, often showed strong glutamate-LI and GABA-LI. These data suggest (1) the accumulation of glutamate or glutamate-like substances, especially in the CA3 pyramidal cells, (2) the excitation of the GABAergic neurons and their subsequent uptake of GABA, and (3) the sequestration of the extracellular neurotransmitters by astrocytes in the postischemic period.
利用沙土鼠单侧脑缺血1小时模型，通过免疫细胞化学方法检测了缺血后大脑中谷氨酸和γ-氨基丁酸（GABA）的重新分布情况。在大脑新皮层，大多数神经元在再灌注5小时后经历恢复过程，而海马体中的神经元则受到不可逆损伤。再灌注后，海马CA3区退化的锥体细胞中谷氨酸样免疫反应性（LI）显著增加，而在新皮层和海马CA1区，锥体细胞的谷氨酸-LI仅略有增加。在大脑新皮层和海马体中，再灌注后与GABA能神经元的神经突相对应的神经毡中GABA-LI阳性小点均增多。虽然未缺血侧的星形胶质细胞既不显示谷氨酸-LI也不显示GABA-LI，但再灌注后观察到的肿胀星形胶质细胞及其足突常常显示强烈的谷氨酸-LI和GABA-LI。这些数据表明：（1）谷氨酸或谷氨酸样物质的蓄积，尤其是在CA3锥体细胞中；（2）GABA能神经元的兴奋及其随后对GABA的摄取；（3）缺血后星形胶质细胞对细胞外神经递质的隔离。
