Nerve fiber layer astrocytes of the primate retina: morphology, distribution, and density.

The nerve fiber layer of several species of primate has been studied with Golgi silver impregnations and Nissl stains. The morphology, distribution, and density of fibrous astrocytes of the nerve fiber layer are described. Two classes of astrocytes are distinguished: elongated cells whose processes parallel the nerve fiber bundles and cover a rectangular area more than two time longer than wide without vascular contact and stellate cells whose processes conspicuously cross the nerve fiber bundles to cover a slightly oval area and make unspecialized vascular contacts. The density of glial nuclei in the nerve fiber layer is roughly proportional to the thickness of the layer all across the retina, so that higher densities are seen in specialized regions such as the arcuate nerve fiber bundles and near the optic disc.