The evaluation on the mouse model of vascular dementia by repeated ischemia-reperfusion method

Objective To evaluate the mouse model of vascular dementia(VD)established by repeated ischemia-reperfusion method,in order to provide an available animal model for the basic research of VD.Methods 50 Kunming mice were randomly devided into two groups:the control group and VD group.In VD group,mice were subjected for continuously repeated three times ischemia-reperfusion through the ligation of the bilateral common carotid arteries to establish VD model.The behavioral abnormalties were investigated by step-down test and water-maze test.The changes of neurons in hippocampal CA1 were observed through light microscope and choline acetyltransferase(ChAT)in neurons of hippocampus were observed by immunohistochemistry technique.Results In step-down test,the response period of mice in the VD group(125.4±32.5s)was prolonged evidently than control group(24.9±2.9s)(P0.01),and the error times increased(P0.01)on the 29th day after operation.the latent period in the VD group(80±29s)was decreased significantly than control group(200±37s)(P0.01),and the error times increased(P0.01)on the 30th day after operation.In water-maze test,the swimming time of mice in VD group was(143±17)s and(162±11)s on the 29th and 30th day after operation,which was evidently prolonged than that of control group(68s±8s and 52s±5s respectively)(P0.01);and the number of error increased(P0.01).The neurons were damaged and the expression of ChAT decreased(0.086±0.009 vs 0.123±0.015,P0.01).Conclusions The model established by repeated ischemia-reperfusion injury is a reliable VD model,which imitated the clinical intelligent dysfunction of VD.