胡须刺激对大鼠桶状皮质局灶性脑缺血的神经保护作用

目的:研究胡须刺激对大鼠桶状皮质局灶性脑缺血的神经保护作用及可能机制。方法 :18只雄性SD大鼠先行胡须依赖实验,训练达标后随机分为假手术组、模型组和胡须刺激组。在显微镜下结扎右侧大脑中动脉2~3根分支构建大鼠胡须桶状皮质局灶性脑缺血模型,胡须刺激组于缺血3 d后开始刺激大鼠左侧胡须。造模成功后3组大鼠再次行胡须依赖实验直至再次达标,记录各组所需实验次数,并于术后14 d应用超声多普勒检测缺血区周围的血流量,HE染色观察缺血脑组织形态结构变化,免疫组化检测缺血区周围CD34的表达情况并测量微血管密度。结果:与模型组相比,胡须刺激组能显著减少胡须依赖实验再次达标所需次数(P<0.01),提高缺血区血流量(P<0.01),改善病理组织学,提高缺血区周围CD34阳性细胞的表达,微血管密度增多(P<0.01)。结论:胡须刺激对大鼠桶状皮质局灶性脑缺血有保护作用,其机制之一可能与诱导CD34的表达上调,改善脑缺血区的血流灌注有关。

Neuroprotection of whisker stimulation against focal barrel cortex ischemia in rats

Objective:To investigate the protective effect and possible mechanism of whisker stimulation on focal barrel cortex ischemia in rats. Methods: Eighteen male Sprague-Dawley rats, which had been trained to reach criteria by completing a whisker-dependent task, were randomly divided into groups of sham-operation, operation and whisker stimulation. The focal ischemia model of whisker-barrel cortex was established by ligating 2~3 branches of the right middle cerebral artery permanently under microscope. The left side whiskers of the whisker stimulation group were stimulated 3 days after ischemia. The vibrissal function of the three groups was evaluated each day after ischemia until rat reached the criteria again. Meanwhile, we record the needed numbers of trials for complete the task. Local cerebral blood flow was assessed by laser Doppler scanner, brain tissue changes were observed with HE staining, the expression of CD34 and microvessel density (MvD) was detected with immunohistochemistry method 14 d after ischemia. Results: Compared with the operation group, the whisker stimulation group significantly decreased the number of trials that required to reach criteria (P < 0.01), enhanced local cerebral blood flow (P < 0.01), detained the pathologic change of ischemic brain, increased the numbers of CD34 positive cells and also MvD (P < 0.05). Conclusion: Whisker stimulation had protective effects on focal barrel cortex ischemia in rats. One possible machanism may be that whisker stimulation can increase expression of CD34 and enhance local cerebral blood flow.