脑深部电刺激对海人酸致痫大鼠突触外GABAA受体α5亚基的影响

摘要

目的 研究脑深部电刺激(DBS)对海人酸致痫大鼠突触外GABAA受体α5亚基的影响,探讨DBS更好的治疗靶点以及可能的治疗机制.方法 成功制模雄性SD大鼠24只按随机数字表法分为癫痫组、丘脑底核DBS组及海马DBS组.通过行为学、实时荧光定量PCR和Western blot技术,分析突触外GABAA受体α5亚基表达变化情况,及其与DBS治疗癫痫疗效之间的关系.结果 在治疗期间,癫痫组、丘脑底核DBS组及海马DBS组癫痫发作次数分别为(8.5±0.9)次、(2.5±0.9)次、(1.9±0.6)次,丘脑底核DBS组及海马DBS组癫痫发作次数分别与癫痫组比较明显减少(P＜0.01),且丘脑底核DBS组与海马DBS组癫痫发作次数比较差异无统计学意义(P＞0.05).实时荧光定量PCR检测显示癫痫组、丘脑底核DBS组及海马DBS组α5亚基mRNA表达分别为0.26±0.04、0.62±0.07、0.79±0.05;Western blot显示癫痫组、丘脑底核DBS组及海马DBS组α5亚基蛋白表达分别为0.11 ±0.03、0.36±0.05、0.44±0.04.丘脑底核DBS组、海马DBS组与癫痫组之间α5亚基mRNA及相关蛋白比较,差异有统计学意义(P＜0.01),且丘脑底核DBS组与海马DBS组比较差异有统计学意义(P＜0.01).结论 DBS可以有效抑制癫痫发作,可能与α5亚基的表达水平密切相关,选择海马作为DBS治疗靶点更有效.%Objective To investigate the effects of deep brain stimulation (DBS) to α5 subunit of extrasynaptic GABAA receptor in the kainic acid induced epilepsy rats and to explore the better therapeutic targets and possible mechanism of DBS.Methods 24 male Sprague-Dawley rats were divided randomly into 3 groups:epileptic,the subthalamic nucleus of DBS and the hippocampus of DBS group.The expression of α5 subunit of extrasynaptic GABAA receptor as well as the association with the curative effects of DBS were evaluated by behavioristics,real time fluorogenic quantitative PCR and western blot.Results After the treatment,the seizures numbers of epilepsy in epileptic group 8.5 ± 0.9 were significantly higher than that in the subthalamic nucleus of DBS 2.5 ±0.9 and the hippocampus of DBS group 1.9 ±0.6 (P ＜0.01).the results of Real time PCR demonstrated that the expression of mRNA of α5 subunits in epileptic group 0.26 ± 0.04 were obviously lower than that in the subthalamic nucleus of DBS 0.62 ± 0.07 and the hippocampus of DBS 0.79 ± 0.05 groups (P ＜ 0.01),and the subthalamic nucleus of DBS was lower than that in the hippocampus of DBS groups (P ＜ 0.01).Westen blot demonstrated that the protein expression of α5 subunits in epileptic group 0.11 ± 0.03 were obviously lower than that in the subthalamic nucleus of DBS 0.36 ±0.05 and the hippocampus of DBS 0.44 ±0.04 groups (P ＜0.01),and the subthalamic nucleus of DBS was lower than that in the hippocampus of DBS groups(P ＜ 0.01).Conclusions DBS is effective in controlling epilepsy seizures,which might be related with the expression level of α5 subunits of extrasynaptic GABAAreceptor.The hippocampus as DBS's targetis more effective.