脑缺血时大鼠海马及其生长抑素神经元的超微结构改变

夹闭大鼠双侧颈总动脉２ｈ，对海马ＣＡ１区进行免疫电镜观察，可见实验组ＣＡ１区部分锥体细胞的胞核固缩、核染色质溶解、细胞器减少或消失；部分神经纤维的髓鞘显示轻度变性图像；部分神经末梢变性；星形胶质细胞突起肿胀；小胶质细胞活跃并包裹断离的髓鞘；生长抑素免疫反应阳性神经末梢比对照组显著增多，生长抑素阳性轴突可与阴性树突形成轴－树突触。以上结果提示：缺血可导致海马ＣＡ１区神经元发生不同程度的损伤和胶质细胞

ULTRASTRUCTURAL CHANGS OF HIPPOCAMPUS AND ITS SOMATOSTATIN NEURONS IN RATS DURING CEREBRAL ISCHEMIA

The immunoelectron microscopic observation of rat hippocampal CA1 area was performed after bilateral carotid arteries being occluded with clips for 2 hours.In experimental group some pyramidal neurons displayed karyopyknosis,disruption and disappearance of organelles.The myelin sheaths of part of fibers degenerated.The processes of astrocytes swelled and microglial cells showed active and enveloped broken myelin sheaths.The somatostatin-immunoreactive nerve terminals were much more than that in the control group.The axo-dendritic synapses formed by somatostatin-positive axons with the negative dendrites were observed.The above mentioned results suggested that ischemia may lead to severe damage of neurons in CA1 area and neuroglial reaction,which in turn give rise to feedback excitation of somatostatin neurons and increased somatostatin stimulates survival pyramidal neurons to be excitatory, therefore,participating the pathogenesis of cerebral ischemia.