Recovery of the hopping response after complete spinal cord transection in the cat.

The hopping response reappears in the hind limb of the cat after complete spinal cord transection at postoperative day means = 11.6. This response is hypermetric and slow compared with that in the normal cat and only forward, medial, and lateral hopping can be elicited. Anatomical and physiological changes in the spinal cord which may account for the reappearance of the hopping response are discussed.