Figure 2. Laser scanning confocal images from control and injured retinas labeled with antibodies to nestin, bromodeoxyuridine and glial fibrillary acidic protein. A: In control retinas, apparent anti-nestin labeling (red) due to nonspecific binding of the anti-mouse secondary antibody (see Figure 1B) was observed outlining blood vessels in the outer plexiform layer, while anti-glial fibrillary acidic protein (GFAP, blue) strongly labeled astrocytes in the nerve fiber layer (NFL). B-F: After 3 days of a sustained retinal injury, anti-nestin labeling is more intense and more extensive in all Müller cells, but the degree of intensity varies across the retina as shown in figures B and D. Müller cell nuclei that incorporate bromodeoxyuridine (BrdU, green) are associated with areas of strong anti-nestin labeling in both figures B and D. Anti-nestin labeling of Müller cells is strongly associated with the presence of Müller cell outgrowth, whether at the earliest (C, arrows), or at more advanced stages of glial scar formation (E, D). In some cases, anti-BrdU labeled nuclei were observed in anti-GFAP labeled cells in the NFL indicating that astrocytic proliferation is also a component of the injury response (D, F, asterisks). In this study anti-nestin labeling was not observed in astrocytes. Scale bars represent 20 μm. OLM represents outer limiting membrane; ONL represents outer nuclear layer; OPL represents outer plexiform layer.