Ganglion cell
== Introduction == In neurophysiology, a ganglion cell is a cell found in a ganglion (a cluster of neurons in the peripheral nervous system). Depending on their location and function, ganglion cells can be categorized into several major groups: Retinal ganglion cell (RGC) found in the ganglion cell layer of the retina Cells that reside in the adrenal medulla, where they are involved in the sympathetic nervous system's release of epinephrine and norepinephrine into the blood stream Cells of the sympathetic ganglia Cells of the parasympathetic ganglia Cells of the spiral ganglia == General Morphology == During the late 1800s, early 1900s, Spanish Neuroscientist and Pathologist Santiago Ramón y Cajal proposed Neuron theory which basically introduced the idea that the Nervous system contained cells called the Neuron.