Adaptive Mechanisms of Spinal Locomotion in Cats1

SYNOPSIS. This paper reviews some aspects of locomotor plasticity after spinalisation and after peripheral nerve lesions. Adult cats can recover spontaneous hindlimb locomotion on a treadmill several days or weeks after a complete section of the spinal cord at T13. The kinematics as well as the electromyographic activity are compared in the same animal before and after the spinal section to highlight the resemblance of locomotor characteristics in the two conditions. To study further the mechanisms of spinal plasticity potentially underlying such locomotor recovery, we also summarize the locomotor adaptation of cats submitted to various types of peripheral nerve section of either ankle flexor or extensor muscles or after denervation of the hindpaws’ cutaneous inputs. It is argued that, even in the spinal state, cats have the ability to compensate for such lesions of the peripheral nervous system suggesting that the spinal cord has a significant potential for adaptive plasticity that could be used in rehabilitation strategies to restore locomotion after spinal cord injury.