Morphology and distribution of GFP-positive perivascular mural cells of primary choroidal arteries (Type 1 vessels).

<p>Perivascular GFP-positive mural cells (<b>A</b>) are densely distributed along the length of DiI-perfused large main choroidal arteries (<b>B</b>). Superposition of a z-stack of confocal images for GFP- and DiI-derived signals (<b>C</b>) demonstrates that perivascular mural cells completely envelop the vessel walls. GFP-positive striations of smooth muscle mural cells (<i>arrowhead, C</i>) are visible around vessel walls, indicating the presence of encircling processes that wrap around vessels in a continuous manner. A single frame confocal image through large main choroidal arteries (<b>D</b>) demonstrates that individual mural cells possess rounded protuberant nuclei and long circumferential processes (<i>upper arrowheads</i>). Mural cells and their processes provide a near complete coverage of the choroidal artery walls (<i>arrowheads in lower cross-sectional panel</i>) with no significant gaps between neighboring mural cell processes. Scale bar = 50 µm.