间歇性θ爆发式磁刺激对高血压大鼠胼胝体髓鞘及局部炎症反应的影响

目的探究间歇性θ爆发式磁刺激对慢性高血压大鼠胼胝体区域髓鞘脱失、星形胶质细胞增生和小胶质细胞活化的改善作用。方法对雄性Sprague-Dawley大鼠随机进行双肾双夹术,制作易卒中型肾血管性高血压大鼠模型。术后22周,模型制备成功的高血压大鼠随机接受连续14 d间歇性θ爆发式磁刺激治疗(intermittent theta burst stimulation,iTBS)(高血压iTBS组,n=6)或假性刺激(高血压假刺激组,n=6),假手术大鼠接受假性刺激(假手术假刺激组,n=6)。HE染色观察胼胝体小动脉形态。免疫荧光染色观察胼胝体MBP标记的髓鞘脱失情况。免疫荧光染色观察GFAP标记的星形胶质细胞数量和IBa-1标记的小胶质细胞数量和形态,以评价星形胶质细胞增生和小胶质细胞活化。结果高血压iTBS组和高血压假刺激组出现明显小动脉管壁增厚。与假手术假刺激组相比,高血压假刺激组胼胝体MBP阳性面积比例减少(P<0.01),GFAP阳性细胞和IBa-1阳性细胞数量明显增加(P<0.01),IBa-1阳性细胞胞体增大,突起变粗,分枝变少。iTBS治疗明显增加了高血压大鼠胼胝体MBP阳性面积比例,降低GFAP阳性细胞和IBa-1阳性细胞数量(P<0.01),IBa-1阳性细胞胞体变小,突起变细,分枝变多。结论iTBS治疗可减轻高血压大鼠胼胝体区域髓鞘脱失,抑制星形胶质细胞增生和小胶质细胞活化。

Intermittent theta burst stimulation reduced myelin loss,proliferation of astrocytes and activation of microglia in corpus callosum of hypertensive rats

Objective To investigate the effects of intermittent theta burst stimulation(iTBS)on myelin loss,proliferation of astrocytes and activation of microglia in corpus callosum of chronic hypertensive rats.Methods Male Sprague-Dawley rats were randomly received two-kidney,two-clip procedure to establish stroke-prone renovascular hypertensive rats model or sham-operated procedure.At postoperative week 22,hypertensive rats randomly received iTBS treatment(n=6)or sham stimulation(n=6)for 14 consecutive days.Sham-operated rats also received sham stimulation(n=6).HE staining was used to observe small arteries pathologies.Immunofluorescence of MBP was used to evaluate myelin loss.The number GFAP-labeled astrocytes were observed to evaluate the proliferation of astrocytes.The number and morphology of IBa-1-labled microglia were observed to evaluate the activation of microglia.Results Wall thickness of small arteries was increased in hypertensive rats.Compared to sham-operated rats,hypertensive rats with sham stimulation showed a significant decrease in MBP(+)area fraction and a remarkable increase in the numbers of GFAP(+)cells and IBa-1(+)cells(P<0.01).Soma of IBa-1(+)cells were larger and number of branches were decreased.iTBS treatment significantly increased MBP(+)area fraction,and decreased the numbers of GFAP(+)cells and IBa-1(+)cells(P<0.01).IBa-1(+)cells had smaller soma and thinner branches.Conclusion iTBS reduced the myelin loss in corpus callosum of hypertensive rats,and suppressed the proliferation of astrocytes and activation of microglia.