Myelination organizes axons into distinct domains that allow nerve impulses to propagate in a saltatory manner. The edges of the myelin sheath are sealed at the paranodes by axon-glial junctions that have a crucial role in organizing the axonal cytoskeleton. Here we propose a model in which the myelinated axons depend on the axon-glial junctions to stabilize the cytoskeletal transition at the paranodes. Thus paranodal regions are likely to be particularly susceptible to damage induced by demyelinating diseases such as multiple sclerosis.
Keywords: Caspr (contactin-associated protein); Myelin; NCP1; axon-glial junctions; axonal cytoskeleton; cytoskeletal transition; node of Ranvier; paranode; paranodin.