Evidence that retinal ganglion cell density affects foveal development.

The monkey's foveola normally contains significant numbers of retinal ganglion cells. The somata of foveola cells are larger than those of other cells in the central retina. Their dendritic fields are up to 50 times larger in area than those of nearby cells in the foveal slope. Experimentally induced reductions in the number of ganglion cells in central retina results in alterations in the size and distribution of cells within the foveola. In these animals the foveola is abnormally small and contains an abnormally large number of cells having smaller than normal cell bodies and dendritic fields. These studies indicate that the formation of the foveola as well as the development of the morphology of cells within the foveola and foveal slope depend during development on high densities of retinal ganglion cells within the central retina.