经颅磁刺激后脑梗死大鼠学习记忆与海马c-Fos的表达

Effects of transcranial magnetic stimulation on the abilities of learning and memory and the expression of c-Fos in hippocampus of rats with cerebral infarction

目的:研究经颅磁刺激对脑梗死后大鼠学习记忆功能和脑海马区c-Fos表达的影响。方法:实验于2004-09/12在华中科技大学同济医学院附属协和医院神经内科实验室完成。48只雄性SD大鼠随机分为正常组、模型组、经颅磁刺激组,每组16只。模型组和经颅磁刺激组大鼠采用线栓法制作一侧大脑中动脉闭塞的脑梗死模型。经颅磁刺激组在制模后第2天给予每天2次、每次30个脉冲的经颅磁刺激治疗,疗程4周。每组中的8只大鼠分别于4周后检测Y-迷宫中的学习记忆成绩和梗死侧海马c-Fos的表达。结果:经颅磁刺激组大鼠学习记忆功能明显改善(学习尝试次数:18.36±4.87;记忆再现次数:6.05±1.34),与模型组比较(学习尝试次数:26.40±5.45;记忆再现次数:3.72±1.18),差异均有显著性意义(t=3.65,3.28;P均<0.01);经颅磁刺激组大鼠海马各区c-Fos阳性表达细胞数显著增加(CA1:28.55±3.62,CA2:25.27±3.09,CA3:27.65±3.53,齿状回:34.92±6.56),与模型组比较(CA1:9.42±1.28,CA2:7.58±1.18,CA3:8.63±1.24,齿状回:11.36±2.04),差异均有显著性意义(t=17.22,19.32,17.57,11.87;P均<0.01)。结论:应用转基因技术获得的c-fos基因突变的小鼠,表现出明显的空间学习记忆障碍,提示c-fos等即早基因的激活可能是学习记忆形成的必要条件。经颅磁刺激?

AIM:To investigate the effects of transcranial magnetic stimulation on the lea rning and memory functions and the expression of c Fos in hippocampus of rats a fter cerebral infarction. METHODS:The experiment was carried out in the laboratory of Department of Neur ology,Union Hospital affiliated to Tongji Medical College,Huazhong University of Science and Technology from September to December 2004.Forty eight male SD rat s were randomly divided into normal group(n=16),model group(n=16) and transcrani al magnetic stimulation group(n=16).Rats in the model group and transcranial mag netic stimulation group were made into models of focal cerebral infarction with the method of unilateral middle cerebral artery occlusion.Transcranial magnetic stimulation was given to rats in the transcranial magnetic stimulation group fro m the 2nd day after model establishment,twice a day,30 pulses once for 4 weeks.T he learning and memory results in Y maze test and the expression of c Fos in h ippocampus of infarcted side were detected in 8 rats of each group after 4 weeks respectively. RESULTS:The learning and memory functions of learning attempt times and memory reappearance times were significantly ameliorated in the transcranial magnetic stimulation group(18.36±4.87,6.05±1.34) as compared with the model group(26.40 ±5.45,3.72±1.18)(t=3.65,3.28;P< 0.01);The number of c Fos positive cells in C A1,CA2,CA3 and dentate gyrus regions of hippocampus in the transcranial magnetic stimulation group(28.55±3.62,25.27±3.09,27.65±3.53,34.92±6.56) was signific antly increased as compared with that in the model group(9.42±1.28,7.58±1.18,8 .63±1.24,11.36±2.04)(t=17.22,19.32,17.57,11.87;P< 0.01). CONCLUSION:Mice with c fos gene mutation induced by the transgenic technology manifests obvious spatial learning and memory disorders,which indicates that th e activation of c fos and other immediate early genes may be the necessary con ditions for the formation of learning and memory.Transcranial magnetic stimulati on enhances the expression of c Fos positive cells in each region of hippocampu s, and plays a role in promoting the recovery of learning and memory functions o f rats with cerebral infarction.