The Deposition of Collagen in Relation to Schwann Cell Basement Membrane during Peripheral Nerve Regeneration

The basement membranes sur rounding the Schwann cells of per ipheral myel inated nerve fibers form un in te r rup ted tubes ensheathing the fibers, being continuous across the nodes of Ranvie r (9, 20). Dur ing Wal ler ian degenerat ion, the basement membranes persist and within the spaces enclosed by them (the " S c h w a n n tubes") the Schwann cells proliferate concurrent ly with the removal of the degenerat ing axon and myelin. Longi tudina l columns of cells result, const i tut ing the " b a n d s of Bfingner ." These changes have been described bo th in nerve roots (11, 12) and in the per ipheral nerve t runk (19). Na than ie l and Pease (13) have demonstra ted tha t dur ing degenerat ion after a localized crush injury to the dorsal roots, in the rat, the Schwann cells become surrounded by new basement memb rane and collagen fibrils, which form within the original Schwann tubes. The present communica t ion confirms this finding for rabbi t per ipheral nerve and reports a relationship between the formation of new basement membrane and collagen deposition. M A T E R I A L A N D M E T H O D S