脑皮质微血管梗塞模型中的迟发性神经元死亡

Delayed Neuronal Death Following Thrombosis in Microvessel in Cerebral Cortex in Rats

目的 :探讨脑皮质微血管梗塞后迟发性神经元死亡的发生机制。方法 :应用光化学反应原理 ,静脉注射光敏染科孟加拉红 ,绿色激光透过颅骨对大鼠脑皮质感觉运动区作定向照射 ,形成脑皮质微血管梗塞模型 ,进行神经功能评分、TTC和HE染色光镜观察、透射电镜观察和原位末端标记。结果 :脑皮质微血管梗塞后 48h ,神经功能缺损发展至高峰 ,神经元和内皮细胞损伤最为严重 ,梗塞灶中心神经元以坏死为主 ,半暗带区凋亡细胞数目显著增加。结论 :光化学法诱导大鼠脑皮质微血管梗塞模型中皮质神经元迟发性死亡呈一定的时间和空间分布特征 。

Objective: To investigate mechanism of delayed neuronal death following thrombosis in microvessel in cerebral cortex in rats.Method: A model of cerebral cortical infarct was established by means of photochemical reaction.The fluorescein derivative Rose Bengal was injected intravenously.The intact skull surface was stereotaxically illuminated with green laser.Before and after irradiation the neurological function was evaluated.Brain slices were observed by light microscope after staining with TTC or HE,and transmission electron microscope.Apoptotic cells were measured in slices stained by TUNEL method.Results: 48 hours after thrombosis in microvessel in cerebral cortes microvessel,eurological function defect reached its peak and the severest injury in neurons and endothelial cells was showed.Necrosis of neurons was dominative in infarct core,and count of apoptotic cells was significantly increased in ischemic penumbra.Conclusion: Delayed neuronal death(DND)in model of cerebral thrombosis in cortical microvessel in rats display a definitive temporal and special character.Neuronal apoptosis in ischemic penumbra may be involved in mechanism of DND.