Cognition alteration of rats after focal cerebral ischemia-reperfusion injury

Objective To observe the changes of cognition ability of the middle cerebral artery occlusion(MCAO) rats,following varied lengths of cerebral ischemia-reperfusion.Methods Totally 36 SD rats(female or male) were randomly and equally divided into 3 groups,the sham group,the ischemia 30 min group and the ischemia 90 min group.The model of MCAO was made by occluding the MCA with thread according to (Longa's) method.Behavioral assessment was evaluated by neurological test.Brain tissue damage was detected in the ischemia animals 14 d after the surgery by triphenyl tetrazolium chloride(TTC) staining.Cognition ability was determined by Morris-maze test and P300 test.Results The score of neurological test were both over 2 points of ischemia groups of 30 min and 90 min.And both groups had infarct areas by TTC staining.The results of Morris-maze test and P300 test showed that the ischemia 90 min group were improved significantly in comparison with sham group and the ischemia 30 min group(P0.01).Conclusion Focal cerebral ischemia can result in the cognitive impairment,which is worse along with the extension of ischemic period.