Diversity and Feature Selectivity of Primate Retinal Ganglion Cells

The primate retina transmits visual information to the brain through parallel pathways carried by diverse retinal ganglion cell (RGC) types, each of which encodes specific features in the visual environment. These parallel channels provide input to a variety of brain regions to support both conscious and reflexive visual functions. Although the midget, parasol, and small bistratified pathways have dominated classical models of primate vision, accumulating evidence points to a broader diversity of wide-field RGC types whose functions are less well understood. Recent breakthroughs in single-cell sequencing have provided new insights into the transcriptomic signatures of these wide-field cells, uncovering molecular markers that can be used to link sparse RGC types to their distinct morphologies and physiological functions. This review synthesizes current knowledge about the diversity of wide-field RGCs in the primate retina and highlights recent insights into cells that encode complex visual features, such as direction-selective ganglion cells. We emphasize how integrative methodological approaches are refining our understanding of the roles of different wide-field RGC types in primate vision.