Abstract: AIM: To observe the effects of Capsule Yi-Zhi on the delayed neuronal death in hippocampal CA₁ region and memory function after global cerebral ischemia. METHODS: The model of acute reperfusion injury after cerebral ischemia in rats was made by vertebral and carotid arteries occlusion;after the models were made 1, 2, 4, 8 and 40 d, the neurons in hippocampal CA₁ region were immunohistochemically stained and calculated.The Morris water maze test was carried out to observe the learning and memory capacities in the 40th day. RESULTS: The number of normal neurons was significantly higher in the Capsule Yi-Zhi (100 mg·kg^-1) group than that of the control group.Compared with the control group, the rats in the Capsule Yi-Zhi (100 mg·kg^-1) group decreased time in finding the platform under the water surface in Morris water maze test. CONCLUSION: CYZ has protective effects on neurons in hippocampal CA₁ region, and shows promising effects on learning and memory dysfunction after global ischemia / reperfusion injury.

Key words: Capsule Yi-Zhi, ischemia /reperfusion injury, delayed neuronal death, learning and memory disorder