Ultrastructural localization of GRP179 in the human retina. (A, B) Human cone pedicles showing labeling for GPR179 on ON-BC dendrites. The black spots indicate GPR179-IR and are found around the invaginating ON-BC dendrites (white asterisks). Labeling was not observed in the HC dendrites (black asterisks). (C, D) Human rod terminals showing labeling for GPR179 on ON-BC dendrites. GPR179-IR is found in rod terminals, around the invaginating ON-BC dendrites (white asterisks) and not the lateral HC dendritic elements (black asterisks). Scale bars: 1 μm (A), 500 nm (B–D). R, synaptic ribbon.