Book excerpt: Traditionally, oligodendrocytes have been assumed to play a minor supporting role in the central nervous system and their importance has generally been overlooked. For the first time, this book provides a dedicated review of all of the major aspects of oligodendrocyte biology, including development, organization, genetics, and immunobiology. Later chapters emphasize the importance of this underestimated cell to the mammalian central nervous system by exploring the role of myelin synthesis and maintenance in neural disease and repair. Particular attention is paid to multiple sclerosis (MS), arguably the prime example of an acquired demyelinating disease, with detailed examinations of the current concepts regarding demyelination, oligodendroglial damage, and remyelination in MS lesions.