F-Spondin is required for accurate pathfinding of commissural axons at the floor plate

Neuron. 1999 Jun;23(2):233-46. doi: 10.1016/s0896-6273(00)80776-x.


The commissural axons project toward and across the floor plate. They then turn into the longitudinal axis, extending along the contralateral side of the floor plate. F-spondin, a protein produced and secreted by the floor plate, promotes adhesion and neurite extension of commissural neurons in vitro. Injection of purified F-spondin protein into the lumen of the spinal cord of chicken embryos in ovo resulted in longitudinal turning of commissural axons before reaching the floor plate, whereas neutralizing antibody (Ab) injections caused lateral turning at the contralateral floor plate boundary. These combined in vitro and in vivo results suggest that F-spondin is required to prevent the lateral drifting of the commissural axons after having crossed the floor plate.

Publication types

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

MeSH terms

  • Animals
  • Axons / physiology*
  • Blotting, Western
  • Cell Adhesion / physiology
  • Chick Embryo
  • Cloning, Molecular
  • Extracellular Matrix / metabolism
  • Extracellular Matrix / ultrastructure
  • Growth Substances*
  • Immunohistochemistry
  • Intercellular Signaling Peptides and Proteins
  • Molecular Sequence Data
  • Neural Cell Adhesion Molecules / biosynthesis
  • Neural Cell Adhesion Molecules / pharmacology
  • Neural Cell Adhesion Molecules / physiology*
  • Neurites / physiology
  • Neurites / ultrastructure
  • Peptides*
  • Rats
  • Spinal Cord / cytology
  • Spinal Cord / embryology
  • Spinal Cord / metabolism
  • Spinal Cord / ultrastructure*


  • Growth Substances
  • Intercellular Signaling Peptides and Proteins
  • Neural Cell Adhesion Molecules
  • Peptides
  • Spon1 protein, rat

Associated data

  • GENBANK/AF149302