Figure 4. Laser scanning confocal images of rabbit retinas detached for 4 days and labeled with anti-bromodeoxyuridine (BrdU; red), anti-phosphohistone H3 (green), and anti-vimentin (blue). BrdU was injected intravitreally on day 3. Anti-phosphohistone H3 labeling of mitotic cells is only observed in the outer nuclear layer (ONL). Some, but not all, of the anti-phosphohistone H3-labeled cells are also labeled with anti-BrdU (A, B). The insets in A and B are cropped from the same image but without the red BrdU channel to more easily visualize the phosphohistone H3 labeling (long arrows point to the same nucleus without the BrdU labeling). Many of the anti-phosphohistone H3-labeled nuclei are surrounded by an accumulation of vimentin filaments (A, C, D, short arrows). Figures C and D are the same image but digitally rotated by tilting the z-stack in different directions to reveal the three-dimensional architecture of the vimentin filaments around the mitotic cell. The top and bottom images of the z-stack were omitted to visualize the anti-phosphohistone H3 labeling within this region. Abbreviations: INL represents inner nuclear layer; IPL represents inner plexiform layer; GCL represents ganglion cell layer, OLM represents the outer limiting membrane, ONL represents the outer nuclear layer. Scale bars are equal to 50 µm (A, B) or 20 µm (C, D).