Neuroprotection in demyelinating diseases: The therapeutic potential of the neurotrophins

The myelin sheath has evolved to exert critical influences upon the central and peripheral nervous systems. Recently, the neurotrophins have been implicated in influencing the dynamic and complex signals that occur between neurons and myelinating glial cells - Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system - that regulate myelination. Somewhat surprisingly, the neurotrophins have been found to influence myelination in a complex manner involving both promyelinating and inhibitory signals that can be directed against either neuronal or glial cells that ultimately regulate central and peripheral myelin formation in distinct ways. The neurotrophins and their receptors have also been shown to influence the severity and affect remyelination in distinct in vivo models of demyelinating disease. Together, these data indicate that the selective targeting of neurotrophin receptors to promote remyelination offers an exciting prospect for the treatment of demyelinating diseases.