Axon Growth and Guidance

The growth cone at the tip of an extending axon is exquisitely sensitive to repulsive and attractive guidance cues in its environment. These molecules may be diffusible and work from a distance, or may be bound to a membrane or substrate and work at close range. It is the complex integration of these repulsive and attractive signals that enhance or suppress axon outgrowth, and/or guide the axon to its appropriate target. These molecules play critical roles during nervous system development and may regulate the regeneration during nervous system disease.

Images: Growth Cone Collapse by Semaphorin 6B/Fc. A) A fully extended dorsal root ganglion (DRG) growth cone growing on a laminin-coated tissue culture plate in te presence of beta-NGF. B) A collapsed DRG growth cone following treatment from Semaphorin 6B/Fc.