Figure 2.

Schematic representation of injury and regenerative process involved in peripheral nerves. (A) Represents the intact nerve, with myelin enwrapping healthy axons; (B) The moment where an injury occurs, instantaneous tissue damage happens at the injury site. After a few hours, macrophages gather at the lesion; (C) The normal Wallerian degeneration process starts roughly 1 day after the initial trauma and axons start to disintegrate; Growth factors are released by Schwann cells in the distal end. (D) Enrolment of Galectin-3 macrophages, which contribute to myelin degradation and removal of myelin debris. Growth factors are retrogradely transported to the proximal end, toward the cell body; and (E) The typical degradation of the distal nerve end happens with the participation of the Galectin-3 macrophages and Schwann cells. These cellular components scavenge deteriorated myelin and axonal matter. After the clearance of the debris, Schwann cells proliferate and align, forming the Bunger bands, for future guiding of the regenerating axons. Reproduced with the permission from Rotshenker (2011).