Myelination
The process of forming a myelin sheath — a fatty insulating layer — around nerve fibres, which dramatically increases signal transmission speed. Demyelination is the pathological process in multiple sclerosis. Glatiramer acetate is an approved peptide-based therapy for multiple sclerosis.
Technical Context
Myelin is a lipid-rich membrane wrapped around axons by oligodendrocytes (CNS) or Schwann cells (PNS). Myelin provides: saltatory conduction (action potentials jump between nodes of Ranvier — increasing conduction velocity from ~1 m/s unmyelinated to ~100 m/s myelinated), metabolic support (oligodendrocytes provide lactate to axons), and axonal protection. Demyelinating diseases: multiple sclerosis (autoimmune attack on CNS myelin/oligodendrocytes → inflammation, demyelination, axonal damage → neurological deficits), Guillain-Barré syndrome (autoimmune PNS demyelination). Glatiramer acetate (Copaxone) is a peptide-based disease-modifying therapy for relapsing MS. Its mechanism involves: promoting anti-inflammatory Th2 response, inducing regulatory T cells, and generating glatiramer-reactive T cells that cross-react with myelin antigens and produce neurotrophic factors (BDNF) at inflammatory CNS lesions. Glatiramer reduces relapse rate by approximately 30% and slows disability progression.