The development of the retinofugal projection within the early formed scaffold of axon tracts in the vertebrate CNS

The relative simplicity of the central nervous systems of invertebrates has enabled neurobiologists to study the development of identified neurons in great detail. The insights that these studies have provided are now being applied to the developing vertebrate brain. Both invertebrates and vertebrates follow a similar scheme during early nervous system development, in which a few orthogonally arranged axon tracts establish a simple scaffold in the neuroepithelium. These tracts are then used by projection axons as routes or highways through the developing brain. In the vertebrate brain one of these highways, the tract of the post-optic commissure (tPOC), has been the focus of recent studies. This article describes how the retinofugal projection utilises the scaffold provided by the tPOC. © 1992