Pharmacological aids to locomotor training after spinal injury in the cat

This Topical Review summarizes some of the work we have done mainly in the cat using agonists and antagonists of various neurotransmitter systems inje cted intravenously or intrathecally to initiate ol modulate the expression of hindlimb locomotion after a spinal lesion at T13. The effects of the sam e drugs are compared in various preparations: complete spinal, partial spin al or intact cats. This has revealed that there can be major differences in these effects. In turn, this suggests that although the locomotor rhythm m ight normally be triggered and modulated by the activation of a variety of receptors (noradrenaline, serotonin, glutamate), after spinalization there appears to he a predominance of glutamatergic mechanisms. Recent work also suggests that, in the cat, the integrity of the midlumbar segments is cruci al for the expression of spinal locomotion. Taken together, this work raise s some hope that a targeted pharmacotherapy with better understood drugs an d mode and locus of delivery could become a clinical reality.