Effects of rehabilitative training on recovery of hand motor function: A review of animal studies

Neuromotor systems have the capacity for functional recovery following damage to the central nervous system. This recovery can be enhanced by rehabilitative training. Animal studies in which artificial damage is induced in a specific region of the brain or spinal cord of rodents or monkeys have contributed to our understanding of the effects of rehabilitative training. In this article, I provide an overview of recent studies in which experimental animals were used to investigate the effects of rehabilitative training on motor recovery and brain plasticity. A study from my group in the macaque monkey reported the effects of hand motor training on motor recovery after lesioning of the primary motor cortex (M1) or the corticospinal tract at the cervical level. In monkeys that had undergone extensive post-lesion training, manual dexterity recovered to previous levels. Rehabilitative training was more effective in promoting recovery of manual dexterity when initiated immediately after the corticospinal tract lesion rather than 1 month later. Both functional brain imaging and gene expression analyses suggest that functional and structural changes may occur in undamaged motor areas during recovery of hand function after M1 or corticospinal tract lesions.