GLIA CELLS OF THE MONKEY RETINA .2. MULLER CELLS

In this paper, for the first time a quantitative description of the mo rphology and distribution of Muller cells in the macaque monkey retina using immunohistochemistry and high resolution confocal laser scannin g microscopy is given. By their morphological features Muller cells ar e ideally adapted to their neuronal environment in the various retinal layers, with a dense network of horizontal processes, especially in t he inner plexiform layer, and close contacts to neuronal somata especi ally in the outer nuclear layer and ganglion cell layer. Morphology va ries with retinal eccentricity, The thickness of the inner trunk incre ases significantly with increasing retinal eccentricity, According to the overall thickness of the retina, Muller cells in central retina ar e longer than in peripheral regions. In the parafoveal region, the out er trunks of Muller cells in the outer plexiform layer are immensely e longated. These Muller fibres can reach lengths of several hundred mic rometers as they travel through the outer plexiform layer from the fov eal centre towards the foveal border where they enter the inner nuclea r layer. Muller cell density varies between 6000 cells/mm(2) in far pe ripheral and peak densities of >30,000 cells/mm(2) in the parafoveal r etina. There is a close spatial relationship between Muller cells and blood vessels in the monkey retina, suggesting a role of Muller cells in the formation of the blood-retinal barrier, in the uptake of nutrie nts and the disposal of metabolites. Copyright (C) 1996 Elsevier Scien ce Ltd.