Migration of Schwann cells in peripheral-nerve regeneration

Schwann cells play a central role in peripheral-nerve regeneration, in whic h it has been shown that the addition of exogenous Schwann cells enhances t he temporal and spatial sequence of events observed in regeneration. In thi s study, the authors investigated the fate of exogenous cells in this proce ss by using fluorescently tagged autogenous Schwann cells in an established rat model of peripheral-nerve regeneration. Tracking labeled cells over a 4-week period revealed early migration of Schwann cells into the proximal n erve segment, followed by a concentration of migrating Schwann cells, leadi ng the proximal growth cone throughout the regenerative process. The early proximal distribution of labeled cells suggests active migration in respons e to nerve damage, with spatial localization at the center of the proximal nerve segment and not the epineural surface. These observations demonstrate an interaction of exogenous Schwann cells with intact nerve tissue in vivo and affirm their role in the directional growth of regenerating axons.