Introduction

It is customary to describe the ganglion cells as the output neurons of the retina. By this is meant that trains of action potentials in the axons of ganglion cells carry encoded messages from the eye to the brain. These messages give rise to conscious visual perception and also contribute to diverse, nonconscious aspects of visual function, including eye movements, modulation of attention, and entrainment of the circadian rhythm. This chapter gives an introduction to the basic morphological and functional properties of ganglion cells in the mammalian retina. Special attention is given to the dominant ganglion cell classes in the primate visual system.