Expression of the Wnt signaling system in central nervous system axon guidance and regeneration

Wnt signaling is crucial for the development of the nervous system, guiding axons to form proper connections. Wnts are expressed in gradients, providing directional information for axon pathfinding and topographic mapping. After spinal cord injury, Wnts are re-induced, forming gradients around the lesion site. These re-induced Wnts may contribute to the retraction of motor axons, making Wnt signaling a potential target for CNS repair. The study of long-distance connections between the brain and spinal cord during development may provide insights for developing therapeutic interventions to repair axons after injury.

• 1
  Wnt gradients guide axons along the anterior-posterior axis in CNS development, as demonstrated by the role of Wnts in directing commissural axons in the spinal cord.
• 2
  Wnt signaling plays a conserved role in topographic map formation, as shown in the vertebrate visual system where Wnt3 gradients are used to establish retinotopic maps.
• 3
  Re-induced Wnt gradients after spinal cord injury may be responsible for the long-range retraction of corticospinal tract axons, with inhibition of Wnt-Ryk signaling promoting axonal growth.