Spinal Cord Nerve Repair Mechanisms Spinal cord injuries are particularly difficult because the injured spinal cord is part of the central nervous system (CNS) which has little ability to regenerate. While the peripheral nervous system (PNS) has a relatively high capacity for regeneration, the CNS is not nearly as efficient owing to present inhibitory factors and an environment that becomes toxic to neurons.
Challenges in CNS Repair
Inhibitory Substances:The CNS context of the CNS is a medieval “glial scar” through which axons must regenerate; it contains trophic substances and metabolic substrates that act as Trojan Horses to lure outgrowing axons, but these must cross this wasteland. Among these are inhibiters like chondroitin sulfate proteoglycans that will inhibit nerve regeneration after spinal cord injuries.
Cell Environment: One of the biggest differences between CNS and PNS is the cellular Types. The Schwann cells of the PNS promote regeneration, while the oligodendrocytes of the CNS do not enhance repair potential. This difference is consequential as it clarifies why peripheral nerves regenerate while central nerves usually do not.
Recent Advances in Research
Neuroprotection and Regeneration: Recently, attention has also been turned to the idea of providing a more permissive substrate for nerve regrowth in the spinal cord. These include investigating stem cell therapies and neurotrophic factors that could potentially boost recovery.
Future therapeutic options: Experimental treatments, namely chondroitinase ABC to degrade gliotic scar constituents, reduced lesion fibrosis in a murine model and provide avenues for human application.
Future Directions
Interestingly, although traditionally thought that spinal cord nerves are irreparable because of this battle between these two forces, current research is finding ways to introduce some new ideas in strategies for revised repair. These include:
Stem Cell Therapy: can neural progenitor cells help axonal reinnervation?
Biomaterials and Gene Therapy: Improplants and gene therapy to provide platforms for healing & functional recovery.
So, in short spinal cord nerves are highly unlikely themselves to repair but the new and exciting research is working to overcome such limitations.
