Auld_2001_Trends.Neurosci_24_309

To cross or not to cross the midline? This is the question that pathfinding axons in the developing CNS must answer. In the past few years the molecular mechanisms involved in this decision process have been determined for neurones. A recent paper now shows that glia are also affected by these same mechanisms and that the presence of glia can tip the balance in favour of repulsion or attraction of neurones to the midline.