remyelinated

Remyelinated is an adjective used to describe axons that have regained a myelin sheath following demyelination. Remyelination is the biological process by which myelin sheaths are reconstructed around damaged or exposed axons, primarily by oligodendrocytes in the central nervous system and by Schwann cells in the peripheral nervous system. Demyelination occurs in various conditions, including multiple sclerosis, traumatic injury, ischemia, and certain infections, and remyelination can restore faster nerve conduction and some metabolic support to axons.

During remyelination, resident progenitor cells, such as oligodendrocyte precursor cells in the CNS, are recruited to the lesion, proliferate, and differentiate into mature myelinating cells. These cells extend processes that wrap new myelin around demyelinated segments. The remyelinated sheath is typically thinner than developmental myelin, and internodes may be shorter, leading to a modified but functional conduction profile. The organization of nodes of Ranvier and other ultrastructural features can be reestablished, though the pattern may differ from intact myelination.

The effectiveness of remyelination tends to decline with age and in chronic disease, and remyelinated fibers can remain more vulnerable to future injury. Therapeutic research aims to enhance remyelination by promoting OPC recruitment and differentiation, mitigating inhibitory signals in the damaged environment, and exploring cell-based or molecular interventions to sustain axonal integrity and improve functional recovery. Remyelinated thus denotes the recovered myelin state following a demyelinating event, reflecting both the rebuilding process and its structural characteristics.