Figure 1. Laser scanning confocal images of control and injured retinas labeled with antibodies to nestin, glial fibrillary acidic protein, and vimentin. A, B: In the noninjured retina, glial fibrillary acidic protein (GFAP, blue) immunoreactivity is restricted to the very thin layer of astrocytes in the nerve fiber layer (NFL). Apparent nestin labeling (red) in vascular structures is due to non-specific binding of the mouse secondary IgG to rat blood vessels as demonstrated by the secondary control data in B. Anti-vimentin (green) labels all of the Müller cells from the NFL into the outer nuclear layer (ONL). C: Following 1 day of injury these three intermediate filament proteins are greatly upregulated with the labeling appearing as streaks extending across the retina. Note the heterogeneity of labeling patterns among Müller cells. D-F: Data shown in C is divided into its three RGB channels to demonstrate the distinctive increases in anti-nestin (E) and anti-vimentin (F) labeling relative to anti-GFAP (D). G, H, I: Three days following injury, the Müller cell labeling pattern appears distinctly different from those at 1 day as GFAP (blue) labeling increases, although the heterogeneity of intermediate filament protein labeling remains. Strongly nestin-positive cells resembling microglial cells in the ONL occur at this time point (G, arrows), while Müller cells expressing predominately nestin begin to show the formation of glial scars in the subretinal space (I, arrow). Scale bars represent 20 μm. OPL represents outer plexiform layer; OLM represents outer limiting membrane.