Glial regulation of the axonal membrane at nodes of Ranvier

Curr Opin Neurobiol. 2006 Oct;16(5):508-14. doi: 10.1016/j.conb.2006.08.003. Epub 2006 Sep 1.

Abstract

Action potential conduction in myelinated nerve fibers depends on a polarized axonal membrane. Voltage-gated Na(+) and K(+) channels are clustered at nodes of Ranvier and mediate the transmembrane currents necessary for rapid saltatory conduction. Paranodal junctions flank nodes and function as attachment sites for myelin and as paracellular and membrane protein diffusion barriers. Common molecular mechanisms, directed by myelinating glia, are used to establish these axonal membrane domains. Initially, heterophilic interactions between glial and axonal cell adhesion molecules define the locations where nodes or paranodes form. Subsequently, within each domain, axonal cell adhesion molecules are stabilized and retained through interactions with cytoskeletal and scaffolding proteins, including ankyrins and spectrins.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Animals
  • Axons / metabolism*
  • Axons / ultrastructure
  • Cell Membrane / metabolism*
  • Cell Membrane / ultrastructure
  • Humans
  • Nerve Fibers, Myelinated / metabolism*
  • Nerve Fibers, Myelinated / ultrastructure
  • Neural Cell Adhesion Molecules / metabolism
  • Neuroglia / metabolism*
  • Neuroglia / ultrastructure
  • Ranvier's Nodes / metabolism*
  • Ranvier's Nodes / ultrastructure

Substances

  • Neural Cell Adhesion Molecules