癫痫致大鼠岛叶皮层及海马GABA能神经元亚型变化的形态学观察

Morphological Changes of GABA Neuron Subtypes in Insular Cortex and Hippocampal induced by Epilepsy in Rats

目的以大鼠脑组织岛叶的GABA能神经元为对象,观察癫痫发作后GABA能神经元的不同亚型在岛叶皮层的变化,并将其与海马进行比较。方法采用匹罗卡品癫痫大鼠模型,随机分为正常组和实验组。通过HE染色法研究癫痫后岛叶皮层及海马神经元变化情况,通过免疫组化法比较岛叶皮层和海马中两种GABA能神经元亚型小清蛋白(PV)和生长抑素(SST)能神经元的表达变化。结果 HE染色结果,与正常对照组相比癫痫后岛叶皮层及海马脑区细胞明显离散,细胞水肿明显。免疫组化结果,正常岛叶细胞中PV染色较强,癫痫后3d和30d后PV染色明显减弱(F=21.744,P<0.05),阳性细胞数量减少。癫痫3d后SST染色明显加强,30d后细胞变圆,SST强阳性细胞数量增多(F=17.182,P<0.05),树突中染色强度也增加。海马变化与岛叶相反,PV染色在3d和30d后有明显增强的趋势(F=5.234,P<0.05),而SST则有减弱的趋势(F=21.229,P<0.05)。结论癫痫后岛叶脑区和海马脑区神经元形态及GABA能神经元分布及表达发生变化,提示癫痫后岛叶皮层及海马脑区均受到影响,其变化可能与癫痫自发发作有关。

Objective To observe changes in the insular cortex after seizures different subtypes of GABA neurons and to compare them with the hippocampus. Methods Pilocarpine epilepsy model rats were randomly divided into the normal group,the experimental group. Neurons changes in insular cortex and hippocampal after epilepsy were observed by HE staining. The changes of GABA neuron subtype parvalbumin( PV) and somatostatin( SST) expressed in the insula cortex and hippocampal were compared by immunohistochemical method. Results HE staining results showed that compared with normal control group,after epilepsy island cortex and hippocampus significantly discreted brain cells and cell edema was found. Immunohistochemical results showed that the normal island PV expression strongly,the PV expressed significantly weakened( F = 21. 744,P &lt; 0. 05),the number of positive cells were reduced either at the 3rd day and 30th day after epilepsy. At 3rd day after epilepsy SST staining significantly strengthened and at 30th day after the epilepsy cells became round( F =17. 182,P &lt;0. 05),the number of SST strongly positive cells increased,and dendritic staining intensity was also increased. In the hippocampal hd the opposite trend compared with the insular cortex,PV staining in3 days and 30 days had a strong upward trend( F = 5. 234,P &lt; 0. 05),while weakening trend in SST( F =21. 229,P &lt; 0. 05). Conclusion After epilepsy the neurons’ s morphology,GABA neurons distribution and expression changed in insula and hippocampus. It suggested that after epilepsy island cortex and hippocampus brain regions was affected and the change may be associated with epilepsy spontaneous seizures.