Effects of treadmill training on learning and memory after cerebral ischemia

Objective To investigate the effects of exercise on learning and memory after cerebral ischemia. Methods Ninety Sprague-Dawley rats were randomly divided into a sham-operated group, a model group and a treadmill training group (n=30 for each), which were further subdivided into groups to receive 7 days, 14 days or 28 days of training with 10 rats in each. The training was treadmill running at 10 m/min for 30 min a day. Cerebral ischemia was induced in the model and training groups using permanent, bilateral common carotid artery occlusion. The training began three days after the operation. Morris water maze tests were used to measure the rats′ learning and memory ability, and Nissl staining was employed to detect the survival rates of pyramidal neurons in the CA1 area of the hippocampus. Results The average escape latency in the treadmill trained group had shortened significantly by day 7, then further by days 14 and 28. It was significantly shorter than the model group′s average at each time point. The average platform crossing time increased significantly compared with the model group′s average. Few dead neurons were observed in the sham-operated group. On days 14 and 28 the average survival rate of pyramidal neurons in the model group was significantly lower than in the treadmill training group or the sham-operated group, though there was no significant difference on day 7. Conclusion Treadmill training can improve learning and memory after cerebral ischemia, at least in rats. Better effects can be observed after longer training. Key words: Cerebral ischemia; Treadmill training; Learning and memory; Exercise