Functional rewiring of brain and spinal cord after injury: the three Rs of neural repair and neurological rehabilitation.

Gains in the use of the upper extremities and in walking after brain and spinal cord injury or stroke depend especially upon the effectiveness of spared sensorimotor nodes in the networks for motor control. Biological interventions for neural repair and motor recovery may involve strategies that replace cells or signalling molecules and stimulate the regrowth of axons. The greatest success of these interventions will depend upon the functional incorporation of spared and new cells and their processes into motor networks. The distributed and modular organization of the motor neurons of the cortex and spinal cord offer a substrate that arranges or represents particular patterns of movement, yet is highly adaptable to training. Neurological impairments and related disabilities can be reduced through rehabilitative retraining protocols that engage these critical components of the sensorimotor network to promote use-dependent adaptations and functional rewiring.