Physical Exercise Improves Cognitive Outcomes in 2 Models of Transient Cerebral Ischemia

Background and Purpose-Preclinical studies suggest that exercise can enhance cognition after cerebral ischemia but often use long training regiments and test cognition during or acutely after training. The cognitive changes may result from enhanced physical fitness and may only provide acute benefit. We sought to determine whether a short period of exercise after cerebral ischemia could improve cognitive outcomes when measured days after completion of exercise training in 2 cerebral ischemia models. Methods-Focal or global cerebral ischemia was induced in Sprague-Dawley rats. Rats recovered (3-4 days) then were subject to no exercise (0 m/min), mild (6 m/min), moderate (10 m/min), or heavy (15-18 m/min) treadmill exercise (5-6 days). Cognition was tested 8 to 10 days after the last exercise session with hippocampal-dependent contextual fear conditioning. Results-A short training period of moderate exercise enhanced cognitive function for a week after exercise completion in both models of cerebral ischemia. Conclusions-Utilization of this exercise paradigm can further the elucidation of exercise-mediated factors involved in cognitive recovery independent of changes in physical fitness.