重复经颅磁刺激对血管性认知功能障碍大鼠学习记忆的干预作用

目的探讨重复经颅磁刺激(rTMS)对血管性认知功能障碍(vascualr cognitive impairment,VCI)大鼠学习记忆的干预作用及海马CA1区脑电功率谱的影响。方法选择健康雄性SD大鼠40只,随机分为以下4组:对照组8只,VCI组10只,低频率组11只,复合频率组11只。对VCI组、低频率组、复合频率组大鼠采用异时性双侧颈总动脉结扎法制备VCI大鼠模型。并于造模前、造模后及经颅磁刺激治疗后行Morris水迷宫实验和立体定位仪定位记录大鼠海马CA1区脑电活动。结果 rTMS治疗5个疗程后,低频率组和复合频率组大鼠Morris水迷宫结果均较VCI组明显改善(P<0.05);而VCI组较造模后5d明显欠佳(P<0.05)。脑电分析显示,rTMS后,低频率组、复合频率组大鼠脑电δ、θ功率较VCI组显著降低,α、β频带脑电功率明显升高,且复合频率组α、β频带脑电功率明显优于低频率组(P<0.05);VCI组α、β频带脑电功率较造模后5d显著降低,δ、θ频带脑电功率较造模后5d显著升高(P<0.05)。结论 VCI大鼠学习记忆功能障碍随时间推移可进行性加重。rTMS干预可在一定程度上对抗VCI造模对大鼠脑功能的损害,延缓VCI的进展。

Effect of repetitive transcranial magnetic stimulation on learning and memory of rats with vascular cognitive impairment

Objective To study the effect of repetitive transcranial magnetic stimulation(rTMS) on learning,memory and hippocampal CA1 area EEG frequencies of rats with vascular cognitive impairment(VCI).Methods Forty healthy male SD rats were randomly divided into control group(n=8),VCI group(n=10),low frequency(LF) group(n=11) and high and low frequency(HLF) group(n=11).A VCI rat model was established by ligating the bilateral common carotid arteries.EEG frequencies in hippocampal CAl region were recorded during the Morris water maze test with a stereotaxic device before and after the VCI model was established.Results Morris water maze test showed that the EEG frequencies in hippocampal CAl region were significantly higher in LF and HLF groups and significantly lower in VCI group after 5 courses of rTMS(P<0.05).EEG frequencies analysis displayed that the δ and θ power was significantly lower whereas the α and β power was significantly hugher in VCI group than in LF group and HLF group after rTMS(P<0.05).The α and β power was significantly lower while the δ and θ power was significantly higher in VCI group after the VCI model was established(P<0.05).Conclusion The learning and memory dismnesia in VCI rats exacerbates progressively with the prolongation of time.rTMS can protect the rat brain against injury,thus delaying the progression of VCI.