[Schwann cells promote development and repair of nerve cells]

During early development Schwann cells have trophic effects on neurons with outgrowing axons. Later these cells are responsible for myelination and formation of nodes of Ranvier in the peripheral nervous system, a developmental process with considerable functional significance. In adult nerves, Schwann cells and axons cooperate closely. After nerve injuries, axons degenerate while Schwann cells proliferate and dedifferentiate. The stimulating effects these cells have on axonal regeneration are exploited clinically through the use of nerve grafts for repair. Schwann cells are used experimentally to enhance regeneration of axons in the central nervous system. Tomorrow this may be used clinically--an exciting development.