Understanding the axonal response to injury by in vivo imaging in the mouse spinal cord: A tale of two branches

Axons, the long fibers of nerve cells, have branches. When an axon is injured, how it responds depends on whether the injury is before or after a branch point. If the main axon is injured before a branch, both branches tend to degenerate and then try to regenerate. However, if only one branch is injured near the branch point, the other branch often stabilizes, preventing regeneration of the injured branch. This stabilization may occur because the spared branch maintains synaptic contacts, telling the neuron to preserve what's left rather than attempting a futile regeneration.

• 1
  Axon injury relative to a branch point significantly impacts the degenerative and regenerative response.
• 2
  A spared branch stabilizes the remaining axon structure after injury.
• 3
  Retrograde degeneration after branch injury is often blocked at the bifurcation point.