Glia-neuron interactions at the midline of the developing mammalian brain and spinal cord.

The midline of the developing brain is a place where axon guidance decisions effect the basic wiring pattern related to laterality in both sensory and motor systems. A variety of glial structures that develop along the midline may play crucial roles in directing axons to project to the left or right side of the central nervous system. Several of these glial structures and their association with axons are described. The molecular mechanisms that underlie axons guidance at the midline, in particular, repulsive factors that provide guidance cues via turning signals, are highlighted.