Neuronal guidance - a genetic perspective

Remarkable advances have been made recently to identify the molecules requi red for the development of neural connections within the brain. A range of ligands and receptors have been uncovered that guide extending neurons to a ppropriate targets and away from inappropriate areas. These molecules point to the signalling mechanisms that guide the neurons and provide entry poin ts for the further dissection of this process. Here I highlight the part ge netic screens and analyses have played in revealing some of the key players in neuronal guidance.