Myelin (source code)
= Myelin
<Myelin> is a multilayered wrapping of glial <cell membrane> around segments of an <axon>. Its lipid-rich layers increase electrical insulation and reduce effective <membrane capacitance>, helping local <electric current> reach the next <node of Ranvier>. <Action potentials> are regenerated at these gaps, producing <saltatory conduction>.<Anatomy and Physiology 2e by J. Gordon Betts and others>[Sections 12.2, Myelin; 12.4, Propagation of the Action Potential]{ref}
A <Schwann cell> makes one myelinated segment in the <peripheral nervous system>; an <oligodendrocyte> can supply segments on several <axons> in the <central nervous system>. The thickness and spacing of <myelin> affect signal timing. In a mouse experiment, altered visual experience changed <myelin> segment length and <optic nerve> conduction, linking experience to the physical geometry of neural transmission.<Dynamic Modulation of Myelination in Response to Visual Stimuli Alters Optic Nerve Conduction Velocity by Ainhoa Etxeberria and others>[Results: visual deprivation, internode length and conduction velocity]{ref}
Back to article page
