Promoting the Regeneration of Axons within the Central Nervous System

Publisher Summary It is noted that the patients with spinal cord injury (SCI) generally experience little functional recovery and suffer from permanent functional deficits. In contrast to the central nervous system (CNS), peripheral nervous system (PNS) axons maintain their plasticity beyond the developmental phase and remain capable of axonal regeneration after injury. The difference between PNS and CNS regenerative capacities may be attributed to the innate differences between CNS and PNS neurons, to the environmental differences presented by CNS glia and PNS Schwann cells or a combination of both. More than two decades have passed since Aguayo and colleagues performed their classic transplantation studies, and since then the spinal cord regeneration field has produced promising targets for drug discovery. Early successes in promoting axon regeneration by Nogo/NgR blockade, Chondroitin sulfate proteoglycans (CSPG) digestion, Rho-associated kinase (ROCK) inhibition, cAMP regulation, and cell transplantation have been illustrated. It is likely that future approaches will involve combinatorial treatments that remove endogenous regeneration roadblocks and encourage the regenerative capacity of injured and noninjured axons.