蛛网膜下腔出血引起大鼠长期认知功能损害及其与海马小清蛋白阳性中间神经元细胞关系

The study of long term dysfunction of cognition and its relationship with parvalbumin-postive interneurons at hippocampus in rats with subarachnoid hemorrhage

目的探讨蛛网膜下腔出血(SAH)后大鼠认知功能损害及其海马区小清蛋白(PV)阳性中间神经元细胞数量变化。方法雄性成年SD大鼠随机分为对照组、假手术组和SAH组。在SAH术后20 w,采用8-臂迷宫实验测定动物的空间认知功能,应用免疫组织化学检测海马区PV阳性中间神经元数量。结果与对照组和假手术组大鼠相比,SAH组大鼠训练时间明显延长(P<0.05);在记忆测试中,间隔1 h、12 h和24 h,3组准确率相似;而间隔2 h、3 h和6 h,SAH组大鼠的记忆正确率明显低于其它两组(P<0.05),显示SAH引起长期记忆功能损害。免疫组化显示,SAH组CA_1区和齿状回(DG)区PV阳性中间神经元细胞数明显低于其它两组(CA_1,P<0.01;DG,P<0.05);CA_2和CA_3区3组之间未见明显差异。结论 SAH可引起长期认知功能损害,这些损害可能与SAH引起海马CA_1和DG区PV阳性中间神经元细胞数减少有关。

Objective To investigate the long-term cognitive impairment and the variation of parvalbumin-postive（ PV） GABAergic interneurons following subarachnoid hemorrhage. Methods The Sprague-Dawley rats were randomly assigned to control,sham and SAH group. Twenty weeks later,the cognitive function was tested by 8-arm maze. Immunohistochemical study was used to detect PV-positive interneurons in hippocampus. Results Compared to the other two groups,SAH rats needed more days for training（ P〈0. 05）,that implied with the decreased ability in learning. In memorial test,all three groups had the same correct rate at the intervals of 1 h,12 h and 24 h,however,SAH rats showed a significant decrease at 2 h,3 h and 6 h（ P〈0. 05）. The number of PV-positive interneurons of SAH rats decreased significantly at CA_1（ P〈0. 01） and dentate gyrus（ P〈0. 05）. Conclusion SAH can cause long-term cognitive deficits in rats,which may cause by the decrease of PV-positive interneurons in CA_1 and DG. SAH leads to persist decrease some interneurons in hippocampus,which may be one of the key reasons for the long lasting cognitive impairment.