Recovery of mechanoreception at the initial stage of regeneration of injured sciatic nerve in rats in conditions of central axotomy of sensory neurons.

The ability of injured afferents of the rat sciatic nerve to regenerate in conditions of damage to their connections with the central nervous system (CNS) as a result of extensive rhizotomy was studied. Recording of spike activity from single nerve fibers demonstrated that rhizotomy, performed simultaneously with nerve injury, had virtually no effect on the initiation of regenerative processes in sensory nerve fibers. The first clear signs of reinnervation of the skin of the foot by decentralized nerve fibers was seen 30 days after nerve injury, which agrees with data obtained in standard conditions, i.e., without rhizotomy. Decentralization of sensory neurons was found to lead to increases in the threshold of perception of a mechanical stimulus in intact and regenerating receptors. However, regenerating receptors showed a significantly more marked decrease in stimulus sensitivity.