脑缺血新模型:大鼠胡须体觉皮层局灶性缺血模型的建立

A new cerebral ischemia model:Establishment of the ischemia model of focal barrel cortex in rats

目的:建立一个简单、可靠的、可以直接研究单一功能变化和组织形态变化之间联系的大鼠胡须体觉皮层局灶性脑缺血模型。方法:大鼠经10%水合氯醛麻醉后,经右侧顶叶皮层处开颅,在显微镜下结扎大脑中动脉的2～3个分支。应用激光多普勒血流仪检测结扎前、后局部脑血流情况,细胞色素氧化酶染色确定胡须体觉皮层和梗死部位的关系,2,3,5-氧化三苯基四氮唑(TTC)染色检测梗死面积大小。胡须依赖实验检测胡须功能。结果:大脑中动脉主要侧支结扎后,梗死中心及周围局部脑血流明显下降。细胞色素氧化酶染色及TTC染色均示梗死区域位于胡须体觉皮层。局灶性缺血3d,测定梗死面积约占全脑面积的15%。梗死形成后大鼠胡须分辨物体纹理的能力下降。结论:选择性的将大鼠具有单一功能的胡须体觉皮层制作成局灶性脑缺血模型,提供了一个较好的研究功能变化和组织形态变化之间联系的脑缺血动物模型。

Objective：To develop a simple,reproducible and reliable rat model of whisker barrel cortex ischemia which can be used to investigate the relation between functional changes and histological changes.Methods：Rats were anesthetized with 10% chloral hydrate（ip）,and the 2-3 branches of right middle cerebral artery（MCA）which supplyed the barrel cortex,were permanently ligated under the direction of microscope.Before and after ligation,local cerebral blood flow was assessed by laser doppler scanner.Barrel pattern on the cortex was examined by the cytochrome oxidase staining and the infarct volume was measured by 2,3,5-triphenyltetrazolium chloride（TTC）staining and vibrissal function was evaluated by completing a whisker-dependent task.Results：The local cerebral blood flow significantly decreased after ligating the branches of MCA.Cytochrome oxidase staining revealed the ischemic region occurred in the barrel cortex.TTC staining revealed that 3 days after ligation the infarct region which targeted on the barrel cortex made up 15% of the whole brain.And a unilateral ischemic lesion to the barrel field impaired the ability of rats to discriminate textures using their whiskers.Conclusion：Whisker barrel cortex ischemia can provide a good cerebral ischemia animal model to investigate the relation between functional changes and histological changes.