Objective To observe the effect on learning and memory abilities of mice on ischemia- reperfusion brain injury,and discuss the protection of Melatonin （MT） on hippocampus neurons of mice after cerebral ischemia-reperfusion injury. Methods 60 healthy mouse were randomly assigned to control group, model group and model treatment group. Model group were adopted by the method of bilateral carotid artery occlusion, the treatment group were injected MT （20 rag. kg-1 three times daily） by intraperitoneal injection, the control group was given equivalence physiological saline simuhaneously. Each group were detected the abilities of learning and memory by Y-type maze three days before sacrificed. Then SOD, NO, MDA and the water content of brain tissues were detected and the change of hippocampus CA3 neurons ultra-structural was observed by electron microscopy. Results Compared with the control group, the ability in learning and memory of treatment group was obviously improved （P 〈 0.05）. Biochemical detection, the content of SOD in treatment group was obviously increased （P 〈 0.05）,while the contents of NO,MDA were sensibly decreased（P 〈 0.05）. By electron microscope,observation the injury of hippocampus neurons in treatment group has been greatly in proved than the non-treated groups. Conclusions MT could significantly improve the mice abilities of learning and memory on ischemia-reperfusion brain injury. And MT might have the neuroprotection effect.
The Journal of Practical Medicine
Learning and memory