Mild to Moderate Early Exercise Promotes Recovery from Cerebral Ischemia in Rats

Abstract

Neurological recovery begins soon after the onset of cerebral ischemia or hemorrhage. Despite this, about 73% of stroke patients suffer from severe neurological disorders.1 Thus, it is essential to use proactive rehabilitation to minimize the longterm disabilities of stroke patients. It is well established that rehabilitation should be conducted as early as possible after the onset of stroke, but a standardized program has not yet been established. 2Rehabilitation from stroke has focused mainly on functional recovery through exercise. Several animal models of cerebral ischemia have shown the benefits of exercise. [3][4][5] In addition, ABSTRACT: Objective: We examined the effects of various exercise intensities on recovery from middle cerebral artery occlusion (MCAO) in rats. Methods: First, we administered a 120-minute left MCAO to male Sprague-Dawley rats and randomly assigned them to one of four groups: no exercise (Group 1), mild exercise (Group 2), moderate exercise (Group 3), and severe exercise (Group 4). Then, we trained the rats for 30 min per day for one week or two weeks. We used a five-point neurological evaluation scale to measure neurological deficits 1-day, 4-days, 7-days, 10-days and 14-days after MCAO and measured infarct volume by use of 2% 2,3,4-triphenyltetrazolium chloride in exercised brains. We also performed immunohistochemistry analysis of the brain to observe reactive astrocytosis at the peri-infarct region. Results: Neurological examination indicated that Group 2 and 3 recovered better than Group 1 after one week and two weeks (p<0.05). Moreover, Group 2 and 3 had reduced brain infarct volume compared with Group 1 after one week (p<0.05). There were no significant differences between Group 4 and Group 1. The thickness of the peri-infarct astrocytosis was significantly reduced in Group 4 relative to Group 1 after one week. There was a significant negative correlation between the extent of reactive astrocytosis and neurological recovery (r= -0.648, p<0.01). Conclusion: This study demonstrates that mild to moderate exercise that begins soon after induced cerebral ischemia promotes recovery and that astrocytes may have an important role in the recovery process.RÉSUMÉ: L'exercice de léger à modéré favorise la récupération de l'ischémie cérébrale chez le rat. Objectif : Nous avons étudié les effets de différentes intensités d'exercice sur la récupération après une occlusion de l'artère cérébrale moyenne (OACM) chez des rats. Méthodes : Nous avons d'abord procédé à une OACM gauche de 120 minutes chez des rats Sprague-Dawley mâles et nous les avons répartis au hasard entre quatre groupes : aucun exercice (groupe 1); exercice léger (groupe 2); exercice modéré (groupe 3) et exercice intensif (groupe 4). Nous leur avons ensuite fait subir un entraînement de 30 minutes par jour pendant 1 ou 2 semaines. Nous avons utilisé une échelle d'évaluation neurologique en cinq points pour mesurer les déficits neurologiques 1, 4, 7, 10 et 14 jours après l'OACM et nous avons mesuré le volume de l'infarctus au ...

Treadmill exercise promotes neuroprotection against cerebral ischemia&ndash;reperfusion injury via downregulation of pro-inflammatory mediators

“…Although intensive exercise may exacerbate brain cell damage,33 numerous experimental data have shown that appropriate exercise protects against ischemic brain injury 34,35. Consistent with these findings, the results demonstrated that appropriate early treadmill exercise treatment improved the neurobehavioral scores and increased the number of survival neurons (Figures 2 and 3), although the underlying mechanisms were not completely elucidated.…”

Physical Exercise Promotes Recovery of Neurological Function after Ischemic Stroke in Rats

“…However, recent rodent studies have indicated that physical exercise acts as an effective rehabilitation program for treatment of ischemic stroke [5,6] by promoting the recovery of the sensory-motor function and preventing deterioration in cognitive ability [7]. Similarly, Lee et al ., have reported that moderate activity can protect against brain injury after a stroke [8]. While the positive effects of early exercise on functional outcome after stroke are widely recognized, their underlying mechanisms are poorly understood.…”

Promoting recovery from ischemic stroke

“…Several experimental studies have demonstrated that physical fitness training, which includes forced and voluntary paradigms, reduces the infarct volume and improves the functional recovery in animal models of ischemic stroke. [118][119][120] Previous experimental stroke studies have moreover identified an increased neuronal plasticity and neurogenesis as structural correlates of improved functional recovery following physical training. [118,121] In a metaanalysis of the efficacy of physical training in animal models of ischemic stroke, including 35 studies with more than 880 animals, we showed that physical training reduced the infarct volume by 14%, improved the cognitive function by 33%, the neuroscore by 13%, and the running function by 7%.…”