Myelin-associated inhibitors in axonal growth after CNS injury

- Regeneration and sprouting are two forms of injury-induced axonal growth.
- Myelin inhibitors modulate axonal sprouting after CNS injury.
- Regeneration elicited intrinsically may be further modulated by myelin inhibitors.
- Promoting sprouting to restore function may be a more attainable near-term goal.

There are multiple barriers to axonal growth after CNS injury. Myelin-associated inhibitors represent one group of barriers extrinsic to the injured neurons. Nogo, MAG and OMgp are three prototypical myelin inhibitors that signal through multiple neuronal receptors to exert growth inhibition. Targeting myelin inhibition alone modulates the compensatory sprouting of uninjured axons but the effect on the regeneration of injured axons is limited. Meanwhile, modulating sprouting, a naturally occurring repair mechanism, may be a more attainable therapeutic goal for promoting functional repair after CNS injury in the near term.