Astrocytes induce oligodendrocyte processes to align with and adhere to axons

Mol Cell Neurosci. 1999 Oct-Nov;14(4-5):385-97. doi: 10.1006/mcne.1999.0788.

Abstract

In order to study the signals that control the onset of myelination, we cocultured highly purified postnatal retinal ganglion cells and optic nerve oligodendrocytes under serum-free conditions that promote their survival for at least a month and found that no myelination occurred. Although the addition of optic nerve astrocytes induced the oligodendrocyte processes to align with, and adhere to, axons, myelination still did not occur. The effect of astrocytes was mimicked by removal of polysialic acid from both cell types using neuroaminidase. These findings provide evidence for a novel role for astrocytes in controlling the onset of myelination by promoting adhesion of oligodendrocyte processes to axons. They also suggest that other, as yet unidentified, cell-cell interactions are necessary to induce the myelination process itself.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Astrocytes / cytology*
  • Astrocytes / physiology
  • Axons / drug effects
  • Axons / physiology*
  • Cell Communication / drug effects
  • Cell Communication / physiology*
  • Cell Culture Techniques / methods
  • Cells, Cultured
  • Membrane Potentials / physiology
  • Myelin Sheath / physiology*
  • Neuraminidase
  • Oligodendroglia / cytology*
  • Oligodendroglia / physiology
  • Optic Nerve / cytology
  • Rats
  • Rats, Sprague-Dawley
  • Retinal Ganglion Cells / cytology
  • Retinal Ganglion Cells / metabolism
  • Retinal Ganglion Cells / ultrastructure
  • Sialic Acids / metabolism
  • Superior Colliculi / cytology
  • Tetrodotoxin / pharmacology

Substances

  • Sialic Acids
  • polysialic acid
  • Tetrodotoxin
  • endo-N-acetylneuraminidase
  • Neuraminidase