癫痫大鼠海马神经元和星形胶质细胞的病理演变

The pathologic alterations of hippocampal neuron and astrocyte in epilepsy rat model

目的探讨癫痫大鼠海马神经元和星形胶质细胞在点燃后各期的病理特点、时序及机制。方法针对匹罗卡品癫痫大鼠模型,行Nissl、免疫组化和HE染色,观察海马神经元及星形胶质细胞的病理变化。结果癫痫持续状态后超急性期(4h),CA3区神经元呈嗜酸性变性、胞浆深染;急性期(24h),嗜酸性变性最为显著,神经元固缩、核仁消失、突起断裂,星形胶质细胞水肿;缄默期(7d),CA3、CA1区及门区神经元大量坏死、脱失,胶质增生肥大,海马构筑紊乱;慢性期(6w),CA3、CA1区出现胶质瘢痕,遗有形态正常的神经元,且颗粒细胞层增厚。结论癫痫时海马神经元先于星形胶质细胞发生病理改变,二者均参与癫痫发生。

Objective To explore the pathologic alterations of neuron and astracyte in epilepsy rat ＇s hippocampus within various phases after onset of status epilepticus （SE）, as well as their schedule and mechanism. Methods Pilocarpine-induced epilepsy rat model was established firstly. Then the rats were sacrificed at definite time points. After stained by Nissl, immunohistochemistry and HE staining, hippocampus sections were observed to detect morphological features. Results In superacute phase （4 h post-SE）, neurons in CA3 region showed acidophilic degeneration and cytoplasm was stained deeply. In acute phase （24 h ）, acidophilic degeneration was the most severest. Many neurons pyknosised with nucleoli disappeared and dendrites ruptured while astracytes hydrepsed. In latent phase （7 d）, massive neurons in CA3, CA1 and hilus regions were found in necrosis or loss. Astrocytes proliferated and hypertrophied, and hippocampus formation deranged. In chronic phase （6 weeks） there appeared glia scar in CA3 and CA1 regions with some normal neurons survival, while granule cell layer broadened. Condusion The pathological damages of neuron are prior to those of astracyte in epilepsy. Both of them are involved in the epileptogenesis.