Figure 1

Intact and injured PNS nerves. A schematic representation of some of the cellular characteristics of (A) intact and (B through E) injured PNS nerves that undergo normal Wallerian degeneration. (A) Intact myelinating Schwann cells enwrap an intact axon and fibroblasts are scattered between nerve fibers. (B) Traumatic injury produces immediate tissue damage at the lesion site (marked by a circle), a gap (rectangle) may be formed between the proximal and distal nerve stumps, and Galectin-3/MAC-2⁺ macrophages accumulate at the lesion site within 24 hours after the injury. (C) Destruction of axons is detected during normal Wallerian degeneration 36 hours after the injury. (D) Recruitment of Galectin-3/MAC-2⁺ macrophages, myelin disintegration, and Galectin-3/MAC-2 expression by Schwann cells begin 48 to 72 hours after injury during normal Wallerian degeneration. (E) Galectin-3/MAC-2⁺ macrophages and Schwann cells scavenge degenerated myelin during normal Wallerian degeneration, and Schwann cells further proliferate and form Bünger bands.