Dr. Frédéric Charron, researcher at the Institut de recherches cliniques de Montréal (IRCM), and his team have shown for the first time that a key molecule of the vascular system directs axons during the formation of neural circuits. This connection between the nervous system and the vascular system could be a good starting point for the development of therapies for neurodegenerative diseases. The discovery will be published June 9 by Neuron.
http://www.sciencedaily.com/releases/20 ... 131330.htm
and it's about the endothelium ---nitric oxide, VEGF and Flk1.
Here's the paper:
VEGF is secreted by the floor plate
Haplodeficiency of Vegf in the floor plate causes axon guidance defects in vivo
Inactivation of Flk1 in commissural neurons causes axon guidance defects in vivo
VEGF/Flk1 activates Src family kinases and induces commissural axon turning in vitro
Growing axons are guided to their targets by attractive and repulsive cues. In the developing spinal cord, Netrin-1 and Shh guide commissural axons toward the midline. However, the combined inhibition of their activity in commissural axon turning assays does not completely abrogate turning toward floor plate tissue, suggesting that additional guidance cues are present. Here we show that the prototypic angiogenic factor VEGF is secreted by the floor plate and is a chemoattractant for commissural axons in vitro and in vivo. Inactivation of Vegf in the floor plate or of its receptor Flk1 in commissural neurons causes axon guidance defects, whereas Flk1 blockade inhibits turning of axons to VEGF in vitro. Similar to Shh and Netrin-1, VEGF-mediated commissural axon guidance requires the activity of Src family kinases. Our results identify VEGF and Flk1 as a novel ligand/receptor pair controlling commissural axon guidance.