Cerebral ischemia leads to neuronal death by apoptosis and necrosis in various regions of the brain especially in the hippocampus. Hippocampus plays a central role in the brain system that is essential for memory function. There are evidences that indicating the physical exercise is neuroprotective and may decreases ischemia/reperfusion injury in rats. However, the role of physical exercise in the hippocampus after cerebral ischemia remains to be investigated. In this study, we specifically investigated pre-ischemia treadmill training effects on CA1 pyramidal cells of hippocampus following cerebral ischemia. Male rats weighing 260-300g were randomly allocated into three groups. The rats in exercise group were trained to run on a treadmill 5 days a week for 4 weeks. Both common carotid arteries were occluded for 20 minutes followed by 4 days of reperfusion. Behavioral examination, apoptosis and necrosis assessment were performed 4 days after ischemia. Findings: Pre-ischemic exercise significantly reduced TUNEL positive cells (P<0.01) and necrotic cell death in the CA1 region of the hippocampus (P<0.05) compared to the ischemia group. Moreover, exercise preconditioning significantly prevents ischemia-induced memory deficits (P<0.05). Conclusion: Thus, our findings indicate that pretreatment with exercise, rescue hippocampal CA1 neurons from ischemia-induced degeneration and prevent memory deficits after cerebral ischemia through preventing neuronal necrosis and apoptosis.
