BIOCHEMISTRY OF DEMYELINATION

The myelin sheath, a lipid-rich multilamellar membrane of relative sta bility, both insulates and enhances conduction in nerve axons. A notab le feature of myelin-specific proteins, in particular myelin basic pro tein, is their susceptibility to proteolytic activity and their enceph alitogenicity, which induces inflammatory demyelination in the CNS. Th e final common pathway of myelin breakdown in vivo is well documented and there is evidence that myelin disruption can be mediated directly by soluble (circulating) factors and for following receptor-driven pha gocytosis by macrophages. However the exact mechanism(s) of demyelinat ion in multiple sclerosis is still unresolved, both antigen-specific a nd - non-specific events having the potential to generate the myelinol ytic process.