The effects of melatonin and/or forced exercise on reorganization of corticospinal tract after focal cerebral ischemia in rats

Abstract

Several mechanisms have been suggested for the rehabilitational approaches after stroke. These include the ipsilateral motor pathway from the unaffected brain to the affected extremities, peri‐lesional reorganization, and recovery of a damaged corticospinal tract (CST). The present study was performed to investigate the effect of melatonin (MT) and/or forced exercise (Ex) on reorganization of CST after focal cerebral ischemia (MCAo) in rats. Following the MCAo surgery, the 8‐week‐old Sprague‐Dawley rats were treated twice daily with MT (10 mg/kg) at 7:00 and 19:00 hr, and were treated with vehicle instead of MT. Also, there were trained twice daily with treadmill exercise (20m/min) at 17:00 and 22:00 hr. At day 7 after MCAo, the brain and spinal cord were collected and performed the histological analysis. It showed that the infarct area was significantly reduced in MT and MT+Ex groups compared to vehicle (p < 0.05, p < 0.01, respectively). Likewise, there were showed the myelination and sprouting of axon in left lateral CST. However, dorsal funiculus was showed a reduction of neural cell on left side in spinal cord. Preliminarily, these results suggest that improvement of functional and structural recovery by the re‐organization of lateral CST following the treatment of MT and MT+Ex, which further suggests the critical rehabilitative therapeutic approaches for recovery from neurological dysfunction due to stroke.