Effect of exercise on functional recovery and dendritic spine morphology after focal cerebral ischemia

Abstract

The promotive effect of rehabilitation after brain stroke has been reported. However, the underlying mechanisms are not clear. The aim of this study is to reveal the effects and the mechanisms of exercise on functional recovery after cerebral ischemia. To induce reproducible permanent cerebral ischemia, male C.B-17/Icr-+/Jcl mice, aged 7weeks were subjected to middle cerebral artery occlusion (MCAO). All mice were divided into 4 groups: sham group, sham + exercise group, MCAO group and MCAO + exercise group. Exercise groups were housed in a cage with a running wheel and let free to run. Behavioral tests were performed using wire hang test and Rota-Rod test at day 14 post-ischemia. Grid walking test was performed during day 2-14 post-ischemia. Then, brains were removed, and the neuronal processes and dendritic spines of pyramidal cells in the layer 5 were visualized by microinjection with Lucifer yellow. Our preliminary results suggest that voluntary exercise can facilitate functional recovery after cerebral ischemia. We will propose the hypothesis that exercise-induced functional recovery after cerebral ischemia is related to the change of dendritic spine morphology.