Typically, a neuron has one or more dendrites, a single axon, a cell body (perikaryon), and a nucleus. By electron microscopy1the cytoplasmic components of a neuronal cell body have been characterized by the presence of aggregates of short segments of granular endoplasmic reticulum (Nissl substance1,2) surrounded by clusters of similar but unattached granules, the ribonucleoprotein particles (RNP), ("Palade granules," or ribosomes), the presence of an unusually large Golgi apparatus, intracytoplasmic filaments, and, usually, a number of electrondense granules.1,3-6 The neuronal perikarya present in the innermost layer of retinal cells are similar in appearance to the large neuronal perikarya found in various ganglia and have therefore become known as "ganglion cells." These ganglion cells make up, for the most part, a single layer of neuronal cell bodies lying between the nerve fiber layer (their axons) and the inner plexiform layer (in part, their dendrites). In the macula,