A Comparative Analysis of the Endocannabinoid System in the Retina of Mice, Tree Shrews, and Monkeys

Figure 5

NAPE-PLD immunoreactivity in calbindin-positive retinal cells. Vertical sections from the mouse retina (first column), tree shrew retina (second column), vervet retina (third column), and macaque retina (fourth column). Confocal micrographs of coimmunolabeling for the synthesizing enzyme NAPE-PLD and a cell-type-specific marker for horizontal cells or cones; in mice and tree shrews, calbindin (CB) labels horizontal cells; in monkeys, CB labels cones. Each protein expression is presented alone in grayscale: NAPE-PLD in the first line and the CB in the second line; then the two are presented merged (third line: NAPE-PLD in magenta and the CB in green). Arrowheads point to the processes of CB-positive cells that express the synthetizing enzyme NAPE-PLD and arrows point to CB-positive cells bodies, which do not express NAPE-PLD. ONL: outer nuclear layer; OPL: outer plexiform layer; INL: inner nuclear layer; IPL: inner plexiform layer. Scale bar = 30 μm.