低频重复经颅磁刺激对血管性痴呆大鼠认知功能的影响

Effects of low-frequency repetitive transcranial magnetic stimulation on cognition function in rats with vascular dementia

目的观察低频重复经颅磁刺激(L-r TMS)对血管性痴呆大鼠认知功能的影响并探讨其神经保护的机制。方法将45只SD大鼠分为假手术组、模型组和治疗组,每组15只。模型组和治疗组利用双侧颈总动脉结扎法制作血管性痴呆模型。治疗组大鼠于造模后给予L-r TMS治疗。利用Morris水迷宫测试检测血管性痴呆大鼠的认知能力;采用免疫印迹方法检测氧化应激指标超氧化物歧化酶(SOD)和丙二醛(MDA)的表达,利用Western blot法检测大鼠海马部位凋亡相关蛋白(Bax、Bcl-2及Caspase-3)的差异情况。结果与假手术组比较,模型组、治疗组造模后及治疗后的逃避潜伏期均延长,目标象限停留时间均减少,差异均有统计学意义(均P<0.05);与模型组比较,治疗组大鼠治疗后逃避潜伏期缩短、目标象限时间延长,差异有统计学意义(P<0.05)。模型组、治疗组大鼠MDA均高于假手术组,SOD均低于假手术组,差异均有统计学意义(均P<0.05)。与模型组比较,治疗组大鼠MDA降低,SOD升高,差异均有统计学意义(P<0.05)。模型组、治疗组Bax、Caspase-3均高于假手术组,差异有统计学意义(P<0.05)。治疗组Bax、Caspase-3均低于模型组,差异有统计学意义(P<0.05)。模型组、治疗组Bcl-2均低于假手术组,治疗组Bcl-2高于模型组,差异均有统计学意义(均P<0.05)。结论 L-r TMS治疗可明显改善血管性痴呆大鼠空间认知功能的损害,其发挥神经保护作用的机制可能与抑制缺血损伤后凋亡途径和氧化应激损伤有关。

Objective To investigate the effects of low-frequency repetitive transcranial magnetic stimulation(L-rTMS)on cognition function in rats with vascular dementia(VD),and its mechanisms. Methods Forty-five SD rats were randomly divided into 3 groups:the sham group,the model group and the treatment group with 15 for each group.The rats of model group and treatment group underwent bilateral common carotid artery occlusion and sham operation was performed in sham group.The rats in the treatment group received L-rTMS treatment.Cognitive function was tested by the Morris water maze method.The expression of oxidative stress indicators SOD and MDA was detected with commercial kits.The protein expression of Bax,Bcl-2 and caspase-3 were detected by Western blot. Results Compared with sham group,the cognitive function of rats in the model group decreased,and the contents of MDA,Bax and Caspase-3 in hippocampus were significantly increased(P<0.05),and the expression of SOD and bcl-2 in hippocampus was significantly reduced(P<0.05).Compared with the rats in the model group,the cognitive ability of rats in the treatment group increased,and the contents of MDA,Bax and Caspase-3 were significantly reduced(P<0.05),and the expression of SOD and bcl-2 was increased in hippocampus(P<0.05). Conclusion L-rTMS treatment can improve the spatial learning and memory ability of VD rats significantly,which may be associated with the inhibition of apoptosis and oxidative stress.