Effects of local anesthesia on persistence of peripherally induced postural asymmetries in rats

Hindlimb flexion induced by direct stimulation of the hindlimb has been observed subsequent to spinal section if an appropriate time interval was allowed to elapse between onset of flexion and spinal cord section. The present series of experiments was conducted to test the possibility that asymmetry persistence is a product of ongoing cutaneous input that continues after stimulation offset and spinal cord section. A local anesthetic (lidocaine) was injected in the general area of stimulation, and its effects on asymmetry were assessed in three experiments. The results generally indicated that ongoing cutaneous input was not a sufficient explanation for persistence of flexion in animals stimulated with intact or severed spinal cords. The data revealed, however, that ongoing cutaneous input may partially explain results of a previous study that employed a "stimulation-wait" preparation to obtain peripherally induced spinal fixation.