Genetic Dysmyelination Models: A Key to the Mechanisms and Regulation of Myelination

The myelin sheath is a highly organized membranous structure that wraps tightly around an axon and provides for the energy-efficient, high velocity propagation of nerve impulses—known as saltatory conduction—without depolarization of adjacent nerve fibers (see chapter by Miller). The myelin sheath is a prerequisite for the development of complex nervous function, as indicated by the appearance of increasing amounts of compact myelin in the nervous systems of the higher vertebrates, with evolutionary development, and by the disease sequelae associated with demyelinating disorders of the nervous system.