经颅磁刺激帕金森病模型小鼠体内神经干细胞的增殖

背景：神经毒素1-甲基-4-苯基-1、2、3、6-四氢吡啶能够诱导类似于在原发性帕金森病所观察到的临床、生化和病理的特征。目的：观察重复经颅磁刺激对帕金森病模型小鼠侧脑室室管膜下区内源性神经干细胞增殖的影响及对情绪障碍的影响。方法：选用雄性C57BL/6J小鼠72只，随机分为 4 组。帕金森病模型组和磁刺激组采用背部皮下注射1-甲基-4-苯基-1、2、3、6-四氢吡啶注射4次制备急性帕金森病模型，末次注射24 h后，对磁刺激组小鼠进行重复经颅磁刺激干预，刺激频率为1 Hz，刺激强度为阈上20%，刺激5个序列，每个序列刺激25次，分别治疗1，3，7 d；假磁刺激组不暴露于磁场下；帕金森病模型组不给予任何处理；盐水对照组皮下注射与帕金森病模型组等量的生理盐水。对重复经颅磁刺激干预前后进行高架十字迷宫实验，以评价其情绪障碍。利用免疫组织化学染色的方法检测室管膜下区巢蛋白阳性细胞数。结果与结论：①高架十字迷宫试验：各组内及各组间在不同时间点，小鼠的开放臂停留时间比例(OT%)差异无显著性意义，但重复经颅磁刺激干预后的小鼠OT%有较明显的下降。②巢蛋白免疫组织化学染色结果：帕金森病模型组较盐水对照组巢蛋白的阳性细胞数于第3天和第7天时明显增高，较假磁刺激组无统计学意义。②磁刺激组较假磁刺激组及帕金森病模型组巢蛋白的阳性细胞数明显增高。③巢蛋白的阳性细胞数随时间的延长而增加，内源性神经干细胞沿一定的路径逐渐往外迁移，第3天时有一部分迁移到胼胝体，到第7天时有一部分能迁移到大脑皮质。说明重复经颅磁刺激能促进内源性神经干细胞增殖，内源性神经干细胞增殖具有时间依赖性。

Transcranial magnetic stimulation promotes proliferation of endogenous neural stem cells of Parkinson’s disease model mice

BACKGROUND: Neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine can induce the clinical, biochemical and pathological characteristics similar to those observed in primary Parkinson’s disease.OBJECTIVE: To observe the effects of repetitive transcranial magnetic stimulation on the proliferation of endogenous neural stem cells of Parkinson’s disease model mice and the mood change. METHODS: A total of 72 male C57BL/6J mice were randomly divided into four groups: normal saline group, Parkinson’s disease model group (model group), sham-repetitive transcranial magnetic stimulation group (sham group) and repetitive transcranial magnetic stimulation group. The mice received 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine injection×4 to establish acute Parkinson’s disease models. The mice in the normal saline group were injected the same volume saline. And 24 hours after the last injection of 1-methyl-4-phenyl-1,2,3, 6-tetrahydropyridine, the mice in the repetitive transcranial magnetic stimulation group received five trains of repetitive transcranial magnetic stimulation, 1 Hz for 25 seconds, at an intensity of 1 Tesla daily for 1, 3, 7 consecutive days. Sham group mice were not exposed to the magnetic field. No treatment was performed in the mice of model group. The mood change was evaluated using the elevated-plus maze testing before and after repetitive transcranial magnetic stimulation treatment. The change in expression of nestin in the subventricular zone was observed by using immunohistochemical technique. RESULTS AND CONCLUSION:(1) Elevated-plus maze testing: There was no statistical significance about percentage of opening arm time accounting for total time among groups and at different time points in each group, but after stimulation, the percentage of opening arm time accounting for total time showed a declined tendency. (2) The results of nestin immunohistochemical staining: Compared to the normal saline group, the number of nestin-positive cells of the model group was increased at days 3 and 7, and there was no statistical significance in the number of nestin-positive cells between model group and sham group; Compared to the sham group and model group, the number of nestin-positive cells of repetitive transcranial magnetic stimulation group were evidently increased; The proliferation of endogenous neural stem cells was time-dependent, endogenous neural stem cells exhibited outward migration gradually along the certain way, and some cells were able to migrate to the corpus callosum at day 3, and even to the cerebral cortex at day 7. Repetitive transcranial magnetic stimulation can promote the endogenous neural stem cells in a time-depended manner.