The Response Properties of Single Ganglion Cells in the Goldfish Retina

Abstract

A cross-section of any vertebrate retina shows a complex pattern in which many types of cells are interconnected. The functions of very few of these cell types are known in any detail. The rods and cones almost certainly absorb the light quanta and are responsible for the initiation of the train of events which culminates in the nerve impulse patterns of the ganglion cells whose axons form the optic nerve. This pat tern of nerve impulses is modified by the intensity, shape, and duration of the illumination falling the retina. In a few types of vertebrate eyes it is also certain that the color of the stimulating light must modify the response patterns of different ganglion cells in a differential fashion. This is a requirement in any system of color vision, and it is fairly certain from behavioral experiments that these animals are able to distinguish colors. Many species of fish apparently can be trained to recognize colors. For this reason the fish retina is an appropriate place to find out how color information is encoded for transmission along the optic nerve. The response patterns of single ganglion cells of the vertebrate retina have been the subject of extensive study since Hartline's successful isolation of the ganglion cells of the frog retina. These response patterns were classified by Hartl ine (1938) into on , off, and on-off ' ' types according to the temporal relationship of the discharge to the illumination. These descriptive terms have been generally accepted by subsequent investigators and are in wide usage today. The response patterns of ganglion cells of a wide variety of other vertebrates have been examined by subsequent investigators. This work has indicated that the discharge patterns are basically similar. The on-off ' ' type is most frequently seen and is looked as playing the dominant role in the functional organization. The analysis of the response relationship