沙土鼠短暂性脑缺血后海马损伤的形态学特征

本实验通过结扎沙土鼠双侧颈总动脉20分钟,再灌流7天内,动态观察背侧海马组织的形态学变化。光镜观察表明:海马各区对缺血的反应性不同,其中以 CA_1区锥体细胞对缺血最为敏感,并且 CA_1区神经元的损伤是迟发性的,再灌流4天后才出现大量神经元的坏死、消失,即“迟发性神经元死亡”(NDN)。电镜下发现:缺血再灌流早期(1～2天),CA_1区神经细胞质内有大量粗面内质网增多。本实验结果表明:短暂性脑缺血所致的海马损伤与脑组织其他区域神经元损伤不同。

A Morphological Study on Hippocampal Damage after Transient Cerebral Ischemia in Gerbils

Gerbils were sacrificed at 12 hours,1,2,4 and 7 days after a 20 minute occlusion of both carotid arteries.The morphological changes of the dorsal hippocampus were observed at varying times of recirculation.Under a light microscope,the histopathologis changes of the hippocampus were observed in several subfields.The neurons in CA_1 sector were particularly sensitive to ischemia.The changes in the CAl subfield were very slow,and almost all of the pyramidal cells in the CAl sector were destroyed and disappeared after a 4 day recirculation. The CAl subfield was selected for electron microscopy,and an increase in the cisterns of the endoplasmic reticulum was observed after the 1-2 day recirculation.The results suggest that the hippocampal damage in CAl sector after transient cerbral ischemia is different from the neuronal damage of the other parts of the brain.Delayed neuronal death and selective vulnerability were the main characteristics.