The relationship between the recovery of learning and memory and the expression of nNOS positive cells in the dentate gyrus of adult rats after focal cerebral ischemia

Objective To observe the relationship between the recovery of learning and memory and the expression of nNOS positive cells in the dentate gyrus (DG) of hippocampus in adult rats after focal cerebral ischemia.Methods In middle cerebral artery occlusion (MCAO) models, bromodeoxyuridine (BrdU) was injected to label proliferative cells. The Y-type electronical maze was used to monitor the recovery of learning and memory of every adult rats.Then BrdU positive cells and nNOS positive cells in DG were observed with immunohistochemistry. Results In MCAO rats,the ability of learning and memory were injured severely, but it recovered better after reperfusion 28-d.BrdU positive cells in DG obviously increased and arrived at the peak on reperfusion 14-d. nNOS expression in DG also increased after reperfusion 7-d and arrived at the peak on reperfusion 28-d. BrdU/nNOS double positive cells increased and arrived at the peak on reperfusion 14-d. Conclusions The ability of proliferation of cells in DG can be improved after focal cerebral ischemia, and some of them express nNOS.It may be related to the recovery of learning and memory after focal cerebral ischemia.