Early and late treadmill training after focal brain ischemia in rats

Treadmill training is increasingly recognized as an effective means to promote rhythmical vigorous walking and also as a useful method of task-related training. The present study endeavored to investigate the effects of early and late treadmill training after ligation of the middle cerebral artery. Forty male Sprague-Dawley rats were subjected to 60 min right middle cerebral artery occlusion (MCAO). All rats were randomly assigned to one of four groups: 24 h group, 2 week no training group, early training group (training started 24 h post MCAO), and late training group (training started 1 week post MCAO). Infarct volume was measured morphometrically. A five-point neurological evaluation scale was used to assess the neurological status of rats. Rats sacrificed 24 h post MCAO had the largest infarct volume (177.8+/-14.3 mm(3)) and the highest neurological score [2(1-4)]. Early treadmill training was found to have significant effects in reducing brain infarct volume and in improving neurologic function when compared with spontaneous recovery. However, the same effects cannot be found in late training. Based on the present findings, we would encourage early treadmill training for ischemic brain recovery.