Walking Again After Spinal Cord Injury

Functional restoration after spinal cord injury has been interpreted as the need to promote long-distance regeneration of severed fibers to their original targets. A radically new and more immediate approach may instead capitalize on the capacity of neuronal circuits within the spinal cord to generate effective postural and locomotor tasks. To exploit this potential, however, the spinal circuitry must be reactivated and remodeled in the context of the post-injury neurophysiological state of the spinal cord. Here, we will introduce neuroprosthetic technologies combining robotic and electrochemical systems that are capable of reactivating spinal locomotor networks after a spinal cord injury and of remodeling spared neuronal pathways in response to training. This new paradigm, termed multi-system neurorehabilitation, restored voluntary control over a range of leg movements in severely paralyzed rats. These findings may inspire new thinking for the design of strategies to return motor function after spinal cord injury and other neuromotor disorders in humans.