The expression of CaN in CA1,CA3 and dentate gyrus of rat model of learning and memory disorder induced by cerebral ischemia

Objective To establish the rat model of learning and memory disorder induced by cerebral ischemia. Immunohistochemical method was employed to detect the CaN expression and localization in CA1,CA3 and dentate gyrus of hippocampal in order to explore the correlation between CaN expression of hippocampal and learning and memory disorder induced by cerebral ischemia. Methods Fifty-four SD male rats were randomly divided into 4 groups: control group, sham operated group, cerebral ischemia group and cerebral ischemia reperfusion group. Set rats models for the later three group. All rats were conducted by the Morris water maze test after one week. And three weeks later, all rats were conducted by the Morris maze memory maintenance trial. After all experiments finished, HE staining and immunohistochemistry method were used to observe cell morphologic change and CaN expression of CA1, CA3 and dentate gyrus, respectively. Results (1) Compared with control group and sham operated group, the most significant pathological changes in hippocampus and impairment of learning and memory disorder were observed in cerebral ischemia reperfusion group. (2) Compared with control and sham operated groups, the numbers of CaN positive cells in cerebral ischemia group and cerebral ischemia reperfusion group were significantly increased (P 0.05). There was no obvious difference of the numbers of CaN positive cells in CA1, CA3 and dentate gyrus between sham operated groups and control group. There was no obvious difference of the numbers of CaN positive cells in CA1 and dentate gyrus between cerebral ischemia group and cerebral ischemia reperfusion group. But the numbers of CaN positive cells in CA3 in cerebral ischemia group was less than that in cerebral ischemia reperfusion group (P 0.05). Conclusions The learning and memory function in cerebral ischemia group and cerebral ischemia reperfusion group were dominantly impaired, and CaN expression in CA1, CA3 and dentate gyrus of hippocampal tissue were increased significantly. The expression of CaN in hippocampal tissue might be correlation with learning and memory disorder of rats, which induced by cerebral ischemia.