Axon Guidance by Diffusible Chemoattractants: A Gradient of Netrin Protein in the Developing Spinal Cord

• DOI: 10.1523/jneurosci.5191-05.2006
• Publication Date: 2006-08-23T16:53:05Z
• Authors: Timothy E. Kennedy; Hao Wang; Wallace Marshall; Marc Tessier-Lavigne
• Keywords: Netrin; Floor plate; Commissure; Slit

Gradients of diffusible long-range attractant and repellent proteins have been proposed to guide growing axons during nervous system development, but such gradients never visualized directly. In the embryonic spinal cord, commissural pioneer a circumferential trajectory floor plate at ventral midline directed by secreted netrin family. chick cord netrin-1 mRNA is expressed cells netrin-2 neural epithelial cells. Antibodies two netrins reveal gradient protein directly in path axons. The itself extends many cell diameters dorsal plate, site expression. A similar distribution has detected rat mouse cord. detection supports operation chemotropic mechanisms developing system.