Abstract
We have investigated the effects of post-lesion training on motor recovery after a lesion of the primary motor cortex (M1). In the monkeys that had undergone intensive daily training after lesion, behavioral indexes used to evaluate manual dexterity recovered to the same level as in the pre-lesion period 1 or 2 months after the lesion Relatively independent digit movements, including precision grip, were restored in the trained monkeys. While the behavioral indexes of manual dexterity recovered to some extent in the monkeys without the post-lesion training, they remained lower than those in the pre-lesion period until several months after M1 lesion. The untrained monkeys frequently used alternate grip strategies to grasp a small object with the affected hand instead of using precision grip. These results suggest that the recovery of precision grip after M1 lesion requires intensive post-lesion training. To investigate the reorganization of neural circuits underlying the training-induced recovery of precision grip, both histochemical and brain imaging studies are in progress. [J Physiol Sci. 2008;58 Suppl:S24]
