cGMP steers axons home

Axonal pathfinding and cyclic nucleotide second messengers have been linked by recent in vitro studies showing that cGMP protects growth cones from collapse induced by repulsive cues. Now, Schmidt et al. show that cGMP is required for axon guidance in vivo, at least in sensory neurons.

To decipher cGMP function during axon growth in vivo, the group deleted the effector kinase cGKIα. This effector was expressed in embryonic sensory axons in wild-type mice, suggesting that sensory neurons might be affected in the deletion mice. Wild-type sensory axons traveled to the spinal cord, where they formed T-like branches and extended in both directions. Axons lacking...