PlexinA2 Limits Recovery from Corticospinal Axotomy by Mediating Oligodendrocyte-Derived Sema6A Growth Inhibition

After adult mammalian CNS injury, axonal growth from both intact and severed fibers is limited. Myelin proteins contribute to this inhibition of axonal growth. The study assessed the role of PlexinA2, a Sema6A receptor, in recovery from adult trauma, finding that mice lacking PlexinA2 showed greater axonal sprouting and functional recovery after corticospinal tract lesions. PlexinA2 contributes to restriction of adult axon growth in the mature CNS, limiting neurological recovery and axonal growth after CNS injury.

• 1
  Outgrowth from adult PlexinA2-/- neurons is not inhibited by Sema6A in vitro.
• 2
  After a pyramidotomy lesion, the PlexinA2-/- corticospinal tract sprouts more than wild type corticospinal fibers.
• 3
  PlexinA2-/- mice recover greater skilled forelimb function than do wild types.