iScience paper

Lesions that cut the corticospinal tract show significant loss of forelimb patterning; however, when the indirect pathways are preserved, rehabilitative training supports the recovery of the lost function. After spinal cord injury (SCI) rehabilitation is thought to mediate re-organization and plasticity of these spared supraspinal-propriospinal circuits leading to recovery of function.

Which of these circuits is instrumental in promoting recovery of skilled forelimb patterning remains unclear. Here we investigated the involvement of cervical propriospinal interneurons (PNs) and rubrospinal neurons (RNs) in recovery of reaching and grasping behavior in rats after bilateral lesions of the corticospinal tract and dorsal columns at C5. These lesions result is a 50% loss in pellet retrieval scores that recovers to normal levels over a 4-weeks period of training.