Oligodendrocyte

Function

Enables saltatory conduction: voltage-gated Nav1.6 channels cluster at nodes of Ranvier between myelinated segments; action potentials effectively jump from node to node, raising conduction velocity from ~1 m/s in unmyelinated fibers to ~100 m/s in large myelinated axons. The g-ratio, axon diameter divided by total fiber diameter, is optimised around 0.6-0.7.

Morphology

A small soma with multiple processes, each ending in a flat spiral of membrane wrapped tightly around an axonal segment. The myelin itself is ~70-80% lipid (cholesterol, galactocerebrosides, plasmalogens) with characteristic proteins MBP and PLP.

Specification

• Receptors: Glutamate; Purinergic
• Location: Throughout the CNS white matter and cortical gray matter.
• Projections: Axons (CNS)
• Firing: Non-spiking
• Markers: MBP; PLP1; MAG; MOG; CNP; MYRF; SOX10; OLIG2 (lineage)
• Developmental origin: Neural tube (Ventral/Dorsal domains)
• Disease: Multiple sclerosis (autoimmune CNS demyelination), Pelizaeus-Merzbacher disease (PLP1 mutations), and the leukodystrophies. Adaptive oligodendrogenesis persists into adulthood and underlies motor learning and cognitive plasticity.
• Cell Ontology: CL:0000128

References

1. McKenzie IA et al. (2014). Motor skill learning requires active central myelination.. Science 346: 318–322 PMID 25324381
2. Miller DJ et al. (2012). Prolonged myelination in human neocortical evolution.. Proc Natl Acad Sci USA 109: 16480–16485 PMID 23012402