Figure 2.

Axonal injuries in compressed PMP22-insufficient nerves. At postcompression days 3 and 5 we obtained semithin sections at transverse 2–3 mm distal to the compression site and examined them under light microscopy. Axons with signs of acute Wallerian degeneration, including extensively collapsed myelin (arrows in A and C), degenerated axons (asterisk in C), and swollen nerve fibers (arrowhead in A), were found in 4 of 11 pmp22^+/− mice (n = 11) but not in wild-type mice (n = 12) (B). Two of these four pmp22^+/− mice were severe (A). These results suggest that Pmp22 insufficiency may make nerve susceptible to axonal injuries in a small portion of animals.