LOCOMOTOR CAPACITIES AFTER COMPLETE AND PARTIAL LESIONS OF THE SPINAL-CORD

This paper first reviews some of the observations made on the locomoto r capabilities of several animal species with a special emphasis on ca ts and including primates and man after complete spinal lesions. We sh ow that animals can perform well-coordinated walking movements of the hindlimbs when they are placed on a treadmill belt and that this locom otion is also adaptable to speed and perturbations. Cats with partial spinal lesions of the ventral and ventrolateral parts of the cord can perform voluntary quadrupedal locomotion overground or on the treadmil l albeit with deficits in weight support and interlimb coordination. W e also show that some drugs such as clonidine (an alpha-2 noradrenergi c agonist) can be used to trigger locomotion in early-spinal cats and discuss the effects of various neurotransmitter systems on the express ion of the locomotor pattern in both complete and partial spinal cats. It is concluded that a pharmacological approach could be used, in com bination with other approaches, such as locomotor training and functio nal electrical stimulation, to improve locomotor functions after spina l cord injuries in humans.