Diameter of axon above which the great majority of axons are myelinated

Range >0.3 µm
Organism Metazoa animals
Reference Harvey A. Swadlow and Stephen G. Waxman (2012), Scholarpedia, 7(6):1451., Axonal conduction delays, link 2nd paragraph
Comments "Conduction velocity increases with both axon diameter, and with myelination and, in the central nervous system, the great majority [of] axons that are > 0.3 microns in diameter are myelinated. The myelin sheath, produced by specialized glial cells, is a compacted spiral of membrane...At diameters of <~0.3 microns, Waxman and Bennett (1972, PMID 4506206) found the benefits of myelin to negligible (Figure 1), and few myelinated axons are found within the CNS at diameters below this value."
Entered by Uri M
ID 110609