Tenascin-R Induces Actin-Rich Microprocesses and Branches Along Neurite Shafts

Mol Cell Neurosci. 2002 Dec;21(4):626-33. doi: 10.1006/mcne.2002.1203.

Abstract

The formation of protrusions along the shaft of neurites might be important in the establishment and refinement of neuronal connections during development. In a search for extracellular signals that affect the formation of microprocesses along neurites we found that the ECM glycoprotein tenascin-R (TN-R) but not other ECM glycoproteins increased the percentage of tectal neurons with actin-rich microprocesses and side branches. Longer actin-based microprocesses were also invaded by microtubuli in their proximal part. The formation of microprocesses by TN-R extending laterally along the neuritic shaft was time- and dose-dependent. In addition to the induction of microprocesses, TN-R increased the size of the growth cone of tectal neurons. A cross-species experiment in combination with blocking antibodies demonstrated that the TN-R-induced effects are mediated by the Ig superfamily member contactin. These observations suggest that TN-R via its neuronal receptor contactin might induce a transition from long-distance growth of tectal interneurons to differentiation, including the formation of microprocesses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / drug effects
  • Actins / metabolism*
  • Animals
  • Cell Adhesion Molecules, Neuronal / drug effects
  • Cell Adhesion Molecules, Neuronal / metabolism*
  • Cell Compartmentation / physiology
  • Cell Differentiation / drug effects
  • Cell Differentiation / physiology*
  • Cell Size / drug effects
  • Cell Size / physiology
  • Cells, Cultured
  • Chick Embryo
  • Contactins
  • Growth Cones / drug effects
  • Growth Cones / metabolism
  • Growth Cones / ultrastructure
  • Immunohistochemistry
  • Microtubules / drug effects
  • Microtubules / metabolism*
  • Neurites / drug effects
  • Neurites / metabolism
  • Neurites / ultrastructure*
  • Receptors, Cell Surface / drug effects
  • Receptors, Cell Surface / metabolism
  • Superior Colliculi / cytology
  • Superior Colliculi / drug effects
  • Superior Colliculi / embryology*
  • Tenascin / metabolism*
  • Tenascin / pharmacology

Substances

  • Actins
  • Cell Adhesion Molecules, Neuronal
  • Contactins
  • Receptors, Cell Surface
  • Tenascin
  • tenascin R