ganglion cell

Quick Reference

A type of neuron found in the inner layer of the retina, nearest the front of the eye, receiving inputs from retinal bipolar cells, which in turn receive inputs from rods and cones. An ON ganglion cell is excited by a spot of light and inhibited by light in a ring surrounding the spot, the inhibition being effected by horizontal cells; an OFF ganglion cell behaves in the opposite way. Two types of ganglion cells are intermixed in the inner layer: large ganglion cells, which form the first stage of the magnocellular system and that do not distinguish between signals from different types of photoreceptors and simply add the signals from all three types of cones together, and small ganglion cells that form the first stage of the parvocellular system and that distinguish between different cone types, from which they add and subtract information, as when a red-minus-green ganglion cell responds only to red light. See also centre-surround receptive field, direction-sensitive neuron, dominator, midget cell, parasol cell, modulator, off-centre cell, on-centre cell, spiral ganglion cell.

Subjects: Psychology.

Reference entries