【作者】 王颖；

【导师】 隋鸿锦；

【作者基本信息】 大连医科大学 ， 人体解剖与组织胚胎学， 2011， 硕士

【摘要】 目的:研究癫痫敏感性形成期大鼠海马CA1区锥体细胞和齿状回颗粒细胞树突棘的可塑性变化特征。方法:采用SD大鼠颈部皮下注射海人酸(10mg/2ml/kg)制作癫痫模型。动物发作达到4级后,即符合癫痫模型的要求。分别在发作后3d和7d,经心脏灌流固定,取脑,制成包含海马结构的脑组织块。脑组织块进行高尔基染色,火棉胶包埋,切片。用Nikon光镜成像系统和NIS-Elements Br图像分析软件在海马结构内选取齿状回分子层和CA1腔隙层测量分析树突棘的形态学特征。正常对照用生理盐水取代海人酸。结果:1齿状回分子层内带树突棘变化树突棘密度在癫痫急性发作后3天显著增多,至发作后7天,树突棘密度持续增加,显著多于正常对照组和KA3d组(P<0.05)。KA3d和KA7d组的无颈短棘数目明显高于对照组(P<0.05),但二者之间无明显差别;与对照组比较,KA3d组有颈长棘数目变化不明显,但有颈长棘平均长度明显下降(P<0.05);KA7d组有颈长棘数目与对照组和KA3d组比较明显增加(P<0.05),而且平均长度恢复到对照组水平。从有颈长棘占树突棘总数的比例上看,KA3d组出现下降趋势,而KA7d组显著增加(P<0.05)。2齿状回分子层外带树突棘变化癫痫急性发作后3天树突棘数量显著增多,至发作后7天,树突棘数量持续增加,显著多于正常对照组和KA3d组(P<0.05)。KA3d和KA7d组的无颈短棘数目明显高于对照组(P<0.05),但二者之间无明显差别;与对照组比较,KA3d组有颈长棘数目和平均长度变化不明显;KA7d组有颈长棘数目与对照组和KA3d组比较明显增加(P<0.05)。从有颈长棘占树突棘总数的比例上看,KA3d组出现下降趋势,而KA7d组显著增加(P<0.05)3齿状回分子层内、外带树突棘变化的比较在KA3d组,内带树突棘密度明显低于外带(P<0.05)。KA7d组内、外带树突棘密度无明显区别,但外带树突的有颈长棘数目以及其在树突总数中的比例均显著多于内带(P<0.05)。4海马CA1区腔隙层树突棘计数癫痫急性发作后3天树突棘数量出现下降趋势,至发作后7天,树突棘数量明显减少(P<0.05)。总之,齿状回分子层内带和外带的树突棘密度在癫痫发作1周内均持续增加,在癫痫发作3天内以短树突为主,从发作后3天至发作后7天,成熟的有颈长棘增加明显。通过内、外带比较可以看出,在癫痫发作后3天,外带的树突棘数目明显多于内带,在癫痫发作后7天,内外带的树突棘密度已无显著差异,但外带的有颈长棘数目却明显多于内带。在癫痫发作3天后,内带的有颈长棘长度明显变短,萎缩。CA1腔隙层树突棘在癫痫发作后3天没有明显下降,而在癫痫发作后7天下降明显。结论:1在癫痫敏感性形成期,齿状回分子层和CA1腔隙层树突棘发生显著的形态学改变,可能参与癫痫敏感性形成机制。2齿状回分子层外带树突棘可塑性变化更显著。3齿状回颗粒细胞树突棘的可塑性变化可能导致CA1锥体细胞的再次损伤。更多还原

【Abstract】 Objective:To study the plasticity characteristics of dendritic spines of CA1 pyramidal cells and dentate gyrus granule cell in duration of sensitive formation of epilepsy on hippocampal.Methods: SD rats were used to produce epilepsy model by subcutaneous injection of kainic acid (10mg/2ml/kg) at neck. Animals, which attack severely in Level 4, meet the requirements of epilepsy models. Respectively after the onset of 3d and 7d, the rats were anesthetizes and the brains were fixed by 4% Paraformaldehyde perfusion through the heart. The brains were removed and made of blocks of brain tissue including hippocampal structure. The brain tissue blocks were performed with Golgi staining. After that, the blocks were embedded with collodion, and then sliced. Nikon light microscope with the imaging system and NIS-Elements Br image analysis software was used to observe and analyeze dendritic spine morphology in the hippocampal dentate gyrus molecular layer and the lacunar layer of CA1. In the normal control group,the kainic acid is replaced with normal saline.Results:1 The inner bend of molecular layer changes in dendritic spinesDendritic spine density in the acute attack of epilepsy was significantly increased after 3 days, and 7 days after the onset of dendritic spine density continues to increase, significantly more than the normal control and KA3d group (P <0.05). The short spines without neck of KA3d and KA7d groups was significantly higher than the number of the control group(P <0.05), but no significant difference between the two. Compared with control group, KA3d group did not change significantly the number of long spine with neck, but the average length of long spine with neck decreased (P<0.05); Compared with control group and KA3d group, the number of long spine with neck in KA7d group significantly increased (P <0.05 ). And the average length of the long spine in KA7d group return to the level of control group. The ratio of long spine and the total number of dendritic spines in KA3d group showed declining trend, while KA7d group was significantly increased (P <0.05).1 The outer bend of molecular layer changes in dendritic spinesDendritic spine density in the acute attack of epilepsy was significantly increased after 3 days, and 7 days after the onset of dendritic spine density continues to increase, significantly more than the normal control and KA3d group (P <0.05). The short spines without neck of KA3d and KA7d groups was significantly higher than the number of the control group(P <0.05), but no significant difference between the two. Compared with control group, KA3d group did not change significantly in the number and average length of long spine with neck; Compared with control group and KA3d group (P <0.05 ). And the average length of the long spine in KA7d group return to the level of control group. The ratio of long spine and the total number of dendritic spines in KA3d group showed declining trend, while KA7d group was significantly increased (P <0.05).3 To compare the changes of dendritic spines between inner and outer bends of dentate gyrus molecular layerIn KA3d group the dendritic spine density of the inner bend was significantly lower than the outer (P <0.05). KA7d group, take-no significant difference between the density of dendritic spines of the inner and outer bends, but the outer spines are the number of long spine with neck and its proportion in the total number of dendrites were significantly more than the inner zone (P <0.05).4The dendritic spines in lacunar layer of hippocampal CA1 area.3 days after acute attack of epilepsy, the number of dendritic spines showed a downward trend, and 7 days after the onset, it was significantly reduced in number of dendritic spines (P <0.05).In short, the density of dendritic spines in the inner and outer bands of dentate gyrus molecular layer have continued to increase within a week in epilepsy, 3 days in the seizures mainly in short dendrites, from the onset after 3 days to 7 days after the onset of the mature Neck-of-spine have increased significantly. Through, by the comparison between outer and inner bends, 3 days after onset of epilepsy, the number of dendritic spines in the outer band take away significantly more than that in the inner band, in 7 days after seizures, there was no significant difference in the density of dendritic spines between the inner and outer bands, but the number of long spine with neck in outer spines was significantly more than that of inner belt.3 days after the seizure, the long spines with neck in the inner band was significantly shorter and atrophy.Lacunar layer of CA1 dendritic spines density in 3 days after seizures,show no significant drop,and decreased significantly after 7 days.Conclusions:1 In the formation of seizure susceptibility , obvious morphological changes occur in the dendritic spines of dentate gyrus molecular layer and CA1 dendritic spines lacunar layer, which may be involved in formation mechanism of seizure susceptibility.2 The plasticity of dendritic spines in outer molecular layer of dentate gyrus is more significant than that in the inner .3 The dentate granule cell plasticity in dendritic spines may lead to the re-injury of CA1 pyramidal cells.更多还原