Morphology, Molecular Characterization, and Connections of Ganglion Cells in Primate Retina

The eye sends information about the visual world to the brain on over 20 parallel signal pathways, each specialized to signal features such as spectral reflection (color), edges, andmotion of objects in the environment. Each pathway is formed by the axons of a separate type of retinal output neuron (retinal ganglion cell). In this review, we summarize what is known about the excitatory retinal inputs, brain targets, and gene expression patterns of ganglion cells in humans and nonhuman primates. We describe how most ganglion cell types receive their input from only one or two of the 11 types of cone bipolar cell and project selectively to only one or two target regions in the brain. We also highlight how genetic methods are providing tools to characterize ganglion cells and establish cross-species homologies.

Automated summary

The eye sends visual information to the brain through over 20 parallel signal pathways, each specialized for features like color, edges, and object motion. Ganglion cell types in humans and primates receive input from specific cone bipolar cells and project selectively to target regions in the brain. Genetic methods are being used to characterize ganglion cells and establish cross-species homologies.