GABAARα1在弥漫性皮质发育障碍鼠大脑皮质和海马中的表达  

Expression of GABAARα1 subunit in cortical region and hippocampal formation of rats with radiation-induced diffuse cortical dysplasia

作　　者：马勋泰[1] 晏勇[1] 王学峰[1] 

机构地区：[1]重庆医科大学附属第一医院神经内科重庆市神经病学重点实验室,重庆400016

出　　处：《重庆医科大学学报》2006年第6期812-817,共6页Journal of Chongqing Medical University

基　　金：重庆市教委应用基础研究基金渝教科(2001)12-29;重庆市医学科技基金(01-1-013)

摘　　要：目的:观察γ-射线辐照诱导的弥漫性皮质发育障碍(DCD)模型鼠大脑皮质和海马结构中γ-氨基丁酸A受体α1亚型(GABAARα1)的表达,探讨其与癫痫发生的关系。方法:建立弥漫性皮质发育障碍大鼠模型,察看其行为、EEG改变,喂养到14～16周处死,采用常规HE染色、Nissl染色和Timm’s硫化银组织化学方法染色,免疫组织化学方法用SABC法,肉眼观察,光镜下观察大脑皮质和海马结构形态及CA3苔藓纤维发芽情况,大脑皮质和海马中GABAARα1阳性细胞形态结构及表达情况,免疫组化图象系统分析。结果:F1代组大鼠有自发性癫痫发作,头皮EEG示小波幅节律为主。小脑畸形、胼胝体发育不全、大脑皮质和海马CA1结节状物,皮质下灰质异位,海马异位神经元。双侧海马CA3区均有苔藓纤维发芽,与正常对照组和假手术组比较有显著差异(P<0.05)。GABAARα1阳性细胞在F1代组的Fr、HL、Par1、Par2、CA1、CA2、CA3和DG区GABAARα1阳性细胞较母鼠组及正常对照组显著减少,有统计学意义(P值均<0.05)。结论:大脑皮质和海马结构异常及抑制性GABAARα1的下调可能是弥漫性皮质发育障碍导致癫痫发作的重要因素之一。Objective： To correlate diffuse cortical dysplasia （DCD） epileptogenicity and the expression of GABAAR α 1 in adult rat with DCD by γ-ray irradiated injury.Methods：To establish γ-ray-induced model of DCD in rat,and newborn Wistar rats were allowed to survive for 14-16 weeks before HE, Nissl Stain, Timm＇s histochemical method and SABC immunohistochemistry. We observed the structure of cortical regions and hippocampal formation with naked eyes and under a light microscope,and assessed the hippocampal mossy fiber sprouting after HE staining,Nissl staining and Timm＇s histochemical method. The comparisons between every two groups were performed with Nemenyi test. We observed the expression of GABAAR α 1 subunit in cortical regions and hippocampal formation in the animal model and quantitatively analyzed using immunohistochemistry of GABAAR α1 subunit.Results ： Normal rats and irradiated pregnant rats didn＇t have any seizure. F1 generation rats had seizure by chance . EEG showed no typical sharp waves , or spikes . In utero irradiation of fetal rats had served as an injury-based animal model of cortical dysplasia and neuronal heterotopia. Exposure of fetal rats to a single dose of γ-irradiation on embryonic day 17 resulted in microcephaly, diffuse cortical dysplasia, neuronal heterotopia, heterotopic neurons in the hippocampus, and bypoplasia of the corpus callosum. The mossy fiber sprouted in hippocampi CA3 area bilaterally, however there was no mossy fiber sprouting in controls or irradiated rats （ P 〈0.05）. Neonatal γ-ray irradiated injury could result in CD in cerebral cortex and mossy fiber sprouting in hippocampi CA3 area. There were chances of GABAAR α 1 subunit in cortical dyspiasia and hippcampal formation.Only the optical densities of GABAAR α 1-immunoreactive neurons located at Fr, HL, Par1,Par2,CA1, CA2, CA3 and DG area were significant different （ P 〈0.05） between the experimental groups and the two control groups. Conclusion ： These studies provide important mechanis

关 键 词：γ-射线 弥漫性皮质发育障碍 苔藓纤维 海马 GABAARα1 

分 类 号：R742.8[医药卫生—神经病学与精神病学]