The role of Schmidt-Lanterman incisures in Wallerian degeneration.

The number of the Schmidt-Lanterman incisures and their intrasegmental distribution were studied at 36 h after transection of the rat sciatic nerve. Examination of teased, proximo-distally oriented, myelinated nerve fibers revealed no difference between the distal and the proximal stump. The results indicate that no proliferation of the incisures is required for the fiber fragmentation: numerous incisures are normally available in the midinternodal area where the degeneration begins.