查看更多>>摘要：目的 探讨经颅直流电刺激(tDCS)对脑梗死大鼠神经行为学、脑血流(CBF)、血管再生、血管内皮生长因子(VEGF)和CD34蛋白表达的影响。 方法 选取成年雄性SD大鼠32只，按照随机数字表法将其分为假手术组(Sham组)、模型组[大脑中动脉闭塞(MCAO)组]、阳极经颅直流电刺激组(A-tDCS组)、阴极经颅直流电刺激组(C-tDCS组)，每组8只。采用线栓法将MCAO组、A-tDCS组、C-tDCS组大鼠制成MCAO模型。造模后24 h开始给予大鼠tDCS刺激，Sham组和MCAO组大鼠均安装电极，但不给予电流刺激，A-tDCS组给予阳极电极刺激，C-tDCS组给予阴极电极刺激，刺激强度200 μA，每日20 min，刺激5 d，休息2 d，再刺激5 d，整体周期共12 d。造模前、造模后24 h和治疗12 d后，采用Longa神经行为学评分法对4组大鼠进行神经行为学评分；造模后3 d和治疗12 d后，采用MRI观察4组大鼠的CBF变化情况；治疗12 d后，采用免疫荧光法观察4组大鼠血管的再生情况，采用Western blot法检测大鼠VEGF和CD34蛋白的表达水平。 结果 造模后24 h和治疗12 d后，MCAO组、A-tDCS组、C-tDCS组大鼠均存在不同程度的神经功能缺损症状。组内比较发现，A-tDCS组、C-tDCS组治疗12 d后的神经行为学评分较造模前和造模后24 h降低(P<0.05)。组间比较发现，A-tDCS组[(1.3±0.4)分]、C-tDCS组[(1.9±0.32)分]治疗12 d后的神经行为学评分较MCAO组[(2.6±0.52)分]低(P<0.05)，且A-tDCS组低于C-tDCS组(P<0.05)。造模后3 d，三维动脉自旋标记(3D-ASL)扫描示MCAO组、A-tDCS组、C-tDCS组大鼠缺血灶周围CBF明显减少，治疗12 d后缺血灶周围CBF有不同程度的增加。A-tDCS组、C-tDCS组的ΔCBF较MCAO组大(P<0.05)，且A-tDCS组ΔCBF较C-tDCS组大(P<0.05)。治疗12 d后，A-tDCS组、C-tDCS组大鼠大脑梗死区的新生微血管密度、脑组织VEGF和CD34蛋白表达较MCAO组高(P<0.05)，A-tDCS组上述指标较C-tDCS组高(P<0.05)。 结论 tDCS可以改善脑梗死大鼠的神经功能缺损症状，促进血管再生，增加CBF，提高VEGF和CD34的表达水平，且阳极tDCS作用优于阴极tDCS。 Objective To explore any effect of transcranial direct current stimulation (tDCS) on neurons, behavior, cerebral blood flow (CBF), vascular regeneration, and the expression of vascular endothelial growth factor (VEGF) and CD34 protein in rats modeling cerebral infarction. Methods Thirty-two adult male Sprague-Dawley rats were randomly divided into a sham surgery group (Sham group), a model group (modeled with middle cerebral artery occlusion, MCAO group), an anode transcranial direct current stimulation group (A-tDCS group), and a cathode transcranial direct current stimulation group (C-tDCS group), each of 8. MCAO models were established in the rats of the MCAO, A-tDCS and C-tDCS groups using thread fixation. Twenty-four hours after successful modeling, both the Sham and MCAO groups were connected with electrodes without current stimulation, while the A-tDCS and C-tDCS groups were given 20 minutes of 200μA anodic or cathodic electrical stimulation daily, 5 days a week for 12 days. Before and 24 hours after the modeling, and then after the 12 days of treatment, the four groups received Longa neurobehavioral scoring. Moreover, three days after the modeling as well as after the 12 days of treatment, changes in CBF were observed using MRI. Any blood vessel regeneration was observed using immunofluorescence methods, and the expression of VEGF and CD34 proteins were detected using western blotting. Results The rats in the MCAO, A-tDCS and C-tDCS groups exhibited various degrees of neurological deficit after the modeling. After the 12 days of treatment the average neurobehavioral scores of the A-tDCS and C-tDCS groups were significantly lower than that of the MCAO group, with the A-tDCS group′s average significantly lower than that of the C-tDCS group. Three days after the modeling, 3D-arterial spin labeling scanning showed a significant decrease in CBF around the ischemic lesion in the MCAO, A-tDCS and C-tDCS groups, but that had increased to varying degrees after 12 days of treatment. The changes in the A-tDCS and C-tDCS groups were significantly larger than in the MCAO group on average, with the former group improving significantly more than the latter. After the 12 days of treatment, new vascularization and the expression of VEGF and CD34 proteins were significantly higher in the A-tDCS and C-tDCS groups than in the MCAO group, with the change in the former group again significantly greater than in the latter. Conclusions tDCS can relieve the symptoms of neurological deficits in rats with cerebral infarction, promote vascular regeneration, CBF, and expression of VEGF and CD34 proteins. Anodic is superior to cathodic stimulation.
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