去大脑皮层血管痴呆模型的建立及评价

A New Model of Cortical Devasculation for Vascular Dementia Research

目的 :建立血管性痴呆模型。方法 :采用 Wistar成年大鼠 ,去除大鼠脑左侧皮层血管建立模型。并结合行为学、神经组织病理学、Ach E组化染色和 Ch HAT、BDNF、trk B免疫组化染色等方法对此模型进行了评价。结果 :去除脑左侧皮层血管后 ,大鼠跳台及水迷官成绩显著下降。HE及 Nissl染色观察到损伤侧皮质、海马 CA1～ CA4区的锥体细胞层及齿状回的颗粒细胞层细胞呈萎缩或呈空泡状的变性。大细胞基底核以及丘脑等处细胞也呈萎缩变性。大鼠损伤侧皮质 Ach E阳性纤维分布稀疏 ,数量明显减少 ,海马 CA1～CA4区 Ach E阳性纤维都有不同程度的减少 ,CA1区减少最明显。大鼠皮质、海马 BDNF、tr KB表达降低 ,大细胞基底核 Ach E、Ch AT、BDNF、trk B阳性神经元数目减少 ,神经元明显萎缩。结论 :去大鼠脑皮层血管痴呆模型 ,能充分模拟血管性痴呆的病理改变 ,且损害部位恒定 ,损及学习、记忆功能 ,实验结果重复性强 ,是研究血管性痴呆较理想的动物模型。

Objective:According to the pathology of VD,we develop a new animal VD model wich is a rat model of cortical devasculation.Method:In this study,we used behavior,AchE histochemical and ChAT,BDNF,trkB immunohistochemical methods to discuss the expression of AchE,ChAT,BDNF,trkB after cortical devasculation.Result:This VD model with devasculation of rat left cortex cause damages in rat cortex and multiple layers and multiple structures beneath the cortex and behaviors.In behavior study,the achievement of leaning and memory of model rats decreased remarkably in the step down test and water maze.In HE and Nissl staining,there is an obvious destruction of cytoarchitecture and distribution of cells in cortex on the side of the lesion,shrinkage and vacuole of cells are found in cortex,especially in the cingulatic cortex.Shrinkage of cells is found in the pyramidal cell layer of CA1\|CA4 subregions of hippocampus and the granule cell layer of dentate.This change is found obviously in the CA1 subregions.The Shrinkage of cells are also found in magnocllular basal nucleus(MBN),The quantity of AchE positive fibers decreased remarkably in the cortex,pyramidal cell layer of CA1\|CA4 subregions of hippocampus and granule cell layer of dentate,especially in the cingulatic cortex and CA1 subregion,this change is more obvious.The quantity of BDNF,trkBpositive neurons decrease obviously in the cortex and hippocampus after cortical devasculation,Those changes are obvious in the cinbulatic cortex and CA1 subregion of hippocampus.The quantity of AchE,ChAT,BDNF,trkB positive neurons decrease obviously in the MBN,and the atrophic cells are also found in MBN,cell body become small,branches become less or even disappear.Conclusion:These results show that this model is an ideal model for the study of VD.