Oligodendrocytes have multiple functions in the central nervous system including mechanical support of neurons, production of myelin sheaths and uptake and inactivation of chemical neurotransmitters released by neurons. Consequently, oligodendrocytes could be involved in the pathology of a number of neurodegenerative diseases. The first chapter of this book examines the range of disorders in which oligodendrocytes play a significant role. In the second chapter, the authors review the effects of microglia on oligodendrocytes in both physiological and pathological conditions. The third chapter focuses on cell transplantation for myelination of axons in spinal cord repair. In the fourth chapter, the authors review data showing the induction of some plasticity of olidogdendrocytes (OL) by growth factors and axon proteins in vitro. Finally, the last chapter is an examination of the potential uses of anti-S100B therapies to treat myelin-related disorders in order to reduce damage and improve recovery, as well as the quality of life of these patients.