During embryonic development, nerve cells hesitantly extend tentacle-like protrusions called axons that sniff their way through a labyrinth of attractive and repulsive chemical cues that guide them to their target.
While several recent studies discovered molecules that repel motor neuron axons from incorrect targets in the limb, scientists at the Salk Institute for Biological Studies have identified a molecule, known as FGF, that actively lures growing axons closer to the right destination. Their findings appear in the June 15 issue of Neuron.
“The most important aspect of our finding is not necessarily that we finally nailed the growth factor FGF as the molecule that guides a specific subgroup of motor neurons to connect to the muscles that line our spine and neck,” says senior author Samuel Pfaff, Ph.D., a professor in the Gene Expression Laboratory, “but that piece by piece, we are uncovering general principles that ensure that the developing nervous system establishes proper neuronal connections.” [Science Daily]