幼鼠致痫后海马区神经元损伤及苔藓纤维发芽的实验研究(英文)

Neuronal damage of hippocampus and mossy fiber sprouting in immature rats with epilepsy

背景:成鼠癫痫持续状态(statusepilepticus,SE)后出现海马CA1区、CA3区及齿状回广泛的神经元脱失和苔藓纤维发芽已成为大量实验的共识,但有关幼鼠该方面研究得出的结论不一。目的:观察幼鼠致痫后海马区神经元的组织病理学改变。设计:随机对照实验研究。地点和对象:实验地点:北京大学人民医院实验动物中心进行。健康生后15～20dWistar幼鼠54只。随机分成3组,每组18只。生理盐水对照组,地西泮干预组,实验组。每组中用于光镜检查、电镜检查和Timm染色各6只。干预:实验组幼鼠采用氯化锂-毛果芸香碱腹腔注射制成幼鼠癫痫持续状态模型,生理盐水对照组以相同液体量的生理盐水取代毛果芸香碱。地西泮干预组在给予毛果芸香碱30min前给予地西泮腹腔注射。在光镜下观察海马结构的形态学改变。透射电镜下进行超微结构观察。Timm法观察苔藓纤维发芽情况。主要观察指标:①各组大鼠海马区的神经元形态学改变。②各组大鼠超微结构改变。③各组大鼠苔藓纤维发芽情况。结果:实验组CA1区和CA3区及齿状回可见许多神经元发生变性和固缩性坏死。CA2区未见明显改变。电镜下海马区神经元胞体浓缩变性,粗面内质网增生,内质网的核糖体脱落,胶质细胞可见有空泡变性。生理盐水对照组和地西泮干预组无明显的超微结构改变。Timm染色见?

BACKGROUND:The appearances of wide neuronal loss and mossy fiber sprouting( MFS) in hippocampus CA1, CA2 area and dentate gyrus in adult rats with status epilepticus(SE) have been recognized by many experiments,but concerning immature rats,the relative studies on this aspect come to different conclusion. OBJECTIVE:To investigate the histopathological changes of hippocampal neurons in immature rats after epilepsy. DESIGN:A randomized and controlled trial study. SETTING and MATERIALS:Setting:The study was conducted in the Experimental Animal Center,People's Hospital of Peking University .Fifty-four healthy immature Wistar rats,15-20 days old, were involved in our study.They were randomly divided into three groups: saline control group,diazepam intervention group,and experimental group,with 18 in each group.Six rats in each group were used to receive optical microscope examination,electron microscope examination, and Timm staining. INTERVENTIONS:Rats in the experimental group were injected abdominally with lithium-pilocarpine to make SE model,and those in the saline control group were injected the same dose of saline instead of pilocarpine.Rats in the diazepam intervention group were injected abdominally with diazepam 30 minutes before pilocarpine injection.Morphological changes of hippocampus were observed under optical microscope,while the ultrastructure was observed under electron microscope, and the MFS condition observed with Timm method. MAIN OUTCOME MEASURES:①morphological changes in the hippocampus of rats in each group.②changes of the ultrastructure of rats in each group.③condition of MFS in rats of each group. RESULTS:More neuronal degeneration and necrosis were seen in the CA1 area,CA3 area,and dentate gyrus in the experimental group. There was no significant change in the CA2 area.The neuronal soma in the hippocampus had inspissated degeneratively under electron microscope,and the rough-surfaced endoplasmic reticulum was hyperplastic,and the ribosome of endoplasmic reticulum dropped, and the glial cells had vacuolated. There was no significant ultrastructure change in the saline control group and the diazepam group. The MFS increased in the molecular layer of dentate gyrus and the hypocentrum of CA3 area[(1.83±0.39) score in the saline control group,(0.42±0.52)score in the diazepam group,and (0.42±0.52)score in the experimental group].There was significant difference in comparison of the saline control group with the experimental group(q=8.00,P< 0.01). CONCLUSION:SE in adult rats can lead to neuronal damage in the hippocampus, and SE in immature rats can also cause the increase of MFS in the hippocampus.