低频重复经颅磁刺激的抗作用及其对癫大鼠海马CA3区膜连蛋白A7表达的影响

Effects of Low-frequency Repetitive Transcranial Magnetic Stimulation on Expressions of Hippocampus CA3 Region Annexin A7 in Rats after Pilocarpine-induced Seizures

目的:观察低频重复经颅磁刺激(rTMS)对大鼠性发作行为及海马CA3区膜连蛋白A7表达的影响。方法:取85只健康雄性SD大鼠,按预处理方式将其分成rTMS组(rTMS刺激+毛果芸香碱致)、对照组(假刺激+毛果芸香碱致)及生理盐水对照组(假刺激+生理盐水)。各组大鼠经相应处理后,rTMS组和对照组(各n=30)大鼠制作氯化锂-毛果芸香碱癫持续状态(SE)模型;生理盐水对照组(n=25)则腹腔注射生理盐水。观察各组大鼠行为表现及SE潜伏期,应用免疫组化法观察膜连蛋白A7表达的动态变化(6 h、24 h、1周、3周、6周)。结果:①rTMS组SE潜伏期为(41.37±5.45)min,与对照组(23.86±4.42)min比较明显延长(P<0.01);②海马CA3区膜连蛋白A7阳性细胞数在各时间点均为对照组最多,rTMS组次之,生理盐水对照组最少(均P<0.05)。但是膜连蛋白A7的表达随时间变化的趋势rTMS组与对照组明显不同。结论:低频rTMS有一定抗作用;低频rTMS可影响大鼠海马CA3区膜连蛋白A7表达并呈现独特的动态变化特点。

Aim： To observe the effects of low-frequency repetitive transcranial magnetic stimulation （rTMS） on rat behavior and the expressions of hippocampus CA3 region annexin A7 in rats after pilocarpine- induced seizures, and explore the possible anti-epileptic mechanisms ofrTMS. Methods： 85 healthy male SD rats were randomly divided into rTMS group （rTMS＋pilocarpine）, control group （sham stimulation＋ pilocarpine）, and NS control group （sham stimulation＋normal saline）, with 30 rats in each of rTMS group and control group, and 25 rats in NS control group. After consecutive corresponding stimulation for 2 weeks respectively, the status epilepticus rat models were established in rTMS group and control group, their behavior were observed and the latent time to status epilepticus was measured. The rats in all groups were killed in different time （6 h, 24 h, 1 week, 3 weeks, 6 weeks）, and the expressions of annexin A7 in the hippocampus CA3 region were investigasted by immunohistochemistry staining. Results： （1） The latent period to status epilepticus in rTMS group （41.37 ± 5.45） was longer than that in control group （23.86 ± 4.42） （P〈0.01）. （2）The positive neurons of annexin A7 at all time points in the rat hippocampus CA3 region were seen most in control group, followed by rTMS group and NS control group respectively. But the changes of annexin A7 with time in rTMS group and control group were totally different. In control group, the annexin A7 soared to peak for 6 h, and then declined gradually over time but did not return to the base line until 6 weeks after termination of seizures. In rTMS group, the annexin A7 was just a little elevated for 6 h, then quickly declined to the lowest for 24 h. Then it increased gradually, and this trend lasted for 6 weeks. In NS control group, the number of positive neurons of annexin A7 did not show significant difference at all time points （P〉0.05 for all time points）. Conclusion： （!） Low-frequency rTMS possesses has some anti- epileptic effects. （g） Low-frequency rTMS has the potential to affect the expression of annexin A7 in the hippocampus CA3 region, and its change with time takes on unique feature. This may be one of the mechanisms that low-frequency rTMS inhibits epileptic seizures and modulates the repair of following epileptic injury.