Remyelination: the true regeneration of the central nervous system.

The myelin sheath, generated by oligodendrocytes in the central nervous system (CNS), is crucial to neuronal function, enabling rapid propagation of nerve impulses and providing trophic support to the axon. Remyelination is the default response to myelin damage. Oligodendrocyte precursor cells, distributed throughout both the grey and white matter of the CNS, are activated in response to myelin injury, undergoing proliferation, migration to the site of damage and differentiation into mature myelinating oligodendrocytes. The end result is complete reconstruction of the area of myelin loss. However, this remarkable regenerative capacity of the CNS becomes less efficient with age and can show clinically significant failure in diseases such as multiple sclerosis. Without the myelin sheath, neuronal function and survival is compromised, leading to axonal degeneration and progressive deterioration in neurological function. Therapies to enhance remyelination could offer a means to prevent the neurological decline of chronic demyelinating disease. In order to develop such therapies, a detailed understanding of the process of remyelination, the major cellular players involved and the mechanisms of remyelination failure is needed. As the intricacies of remyelination continue to be unravelled, effective remyelination therapies are ever closer to becoming a reality.