Microglial cells of the retina

The retina is a highly ordered structure made up of repeating stacks of cells underlying groups of photoreceptor cells. The neuronal cell layers are separated by plexiform layers made up of neuronal processes. In most tissues, the ordered location of F4/80-positive cells is not evident in a single section. This view of the inner plexiform layer of the retina, cut en face, shows that F4/80-positive macrophage (known as microglia) take up a highly-ordered array in which their processes do not overlap. The hexagonal pattern is similar to that of Langerhans cells in the skin. The underlying neuronal cell order has not been documented.