A retinal ganglion cell is a type of neuron located in the retina of the human eye. It receives visual information from photoreceptors through two types of intermediate neurons: bipolar cells and amacrine cells. Retinal ganglion cells transmit both image-forming and non-image-forming visual information to several regions in the brain, including the thalamus, hypothalamus, and midbrain.
- Retinal ganglion cells are located near the boundary between the retina and the central chamber containing the vitreous humour. They collect and process visual information from around forty different types of cells, including rods, cones, bipolar, horizontal, and amacrine cells. Once processed, this information is transmitted via their axons to higher visual centres in the brain
- The axons of ganglion cells form the fibres of the optic nerve, which synapse onto the lateral geniculate nucleus. Axons are long, slender projections of the cell body that typically conduct electrical impulses, known as action potentials, away from the neuron.
- In the fovea at the centre of the macula, a single ganglion cell communicates with as few as five photoreceptors, producing the highest possible resolution of detail. At the retina’s extreme periphery, however, a single ganglion cell receives input from thousands of photoreceptors.
- There are approximately twenty functional types of ganglion cells, which resolve visual information from 120 million rods and cones into a million parallel streams. These cells complete the foundation of visual processing in the retina, encoding the eye’s response to light and forming the fundamental building blocks of vision. Ganglion cells enable this encoding to converge into a unified representation of the visual world, creating the basis for human visual experience.