Effects of voluntary and forced exercises on motor function recovery in intracerebral hemorrhage rats

Motor paralysis is a severe consequence of intracerebral hemorrhage (ICH) that reduces patient quality of life. Rehabilitation is beneficial for stroke patients. However, functional recovery depends on the exercise type, and which factors are effective during rehabilitation are unknown. We aimed to clarify the effect of voluntary and forced exercises for functional recovery in ICH rats. Male Sprague-Dawley rats were divided into three groups: forced treadmill running (F-Ex.), voluntary wheel cage running (V-Ex.) and no exercise (Non-Ex.). The effects of the two exercises on motor recovery were analyzed by determining the motor deficit score and using the beam walking test. Stress and motivation status after rehabilitation were determined by corticosterone concentrations (ELISA) and immunoreactivity of ΔFosB (immunohistochemistry) in the nucleus accumbens, respectively. Significantly enhanced motor functional recovery was observed in the two trained groups compared with that in the Non-Ex. group. Of note, recovery in the V-Ex. group was greater than that in the F-Ex. group. To investigate the motivation and stress related to the exercises, the expression of ΔFosB in the nucleus accumbens and corticosterone concentration were compared after rehabilitation. In the V-Ex. group, there was a significant increase of ΔFosB, and in the F-Ex. Group, there was a high concentration of corticosterone. These data suggest that the effect of training for motor recovery was enhanced by motivation and reduced by stress.