Floor plate chemoattracts crossed axons and chemorepels uncrossed axons in the vertebrate brain

Neuron. 1995 May;14(5):1083-93. doi: 10.1016/0896-6273(95)90347-x.


In the bilaterally symmetrical vertebrate CNS, all developing axons must choose between remaining on the same side of the midline or growing across it. The mechanism underlying this axonal pathfinding is, however, poorly understood. Here we demonstrate that the ventral midline floor plate (FP) chemorepels two types of ipsilaterally projecting axons, one from the alar plate and another from the basal plate in the mesencephalon. We further demonstrate that the FP chemoattracts contralaterally projecting myelencephalic as well as metencephalic axons. The FP at all axial levels displayed both chemoattractive and chemorepellent activities, suggesting that FP chemoattraction and chemorepulsion may be at work throughout the neuraxis. Chemotropic guidance by the FP may therefore play a key role in the establishment of neuronal projection laterality.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Axons / physiology
  • Axons / ultrastructure*
  • Brain / embryology*
  • Brain / ultrastructure*
  • Central Nervous System / embryology*
  • Central Nervous System / metabolism
  • Chemotactic Factors / metabolism
  • Chemotactic Factors / pharmacology*
  • Culture Techniques
  • Mesencephalon / ultrastructure
  • Rats
  • Rats, Wistar
  • Rhombencephalon / ultrastructure


  • Chemotactic Factors