Immunohistochemical labeling of activated Müller cells and astrocytes (GFAP) and Müller cell (GS). (A-D) GFAP. (E-H) GS. (A) WT control retinas show scattered astrocytes and Müller cell endfeet present at outer border of the specimens, as well as isolated Müller cell processes in the IPL. Isolated retinal vessels are labeled in the INL. (B) WT hypo specimens display strong labeling of hypertrophic Müller cell fibers spanning the entire vertical width of the retina. (C) KO control specimens display labeling of scattered astrocytes and Müller endfeet at the outer border of the specimens and isolated blood vessels in the inner layers. (D) KO hypo mice show a discontinuous band of labeled astrocytes and Müller endfeet at the inner border, as scattered retinal vessels in the inner layers. (E) WT control animals reveal strong GS labeling throughout the specimens. (F) In WT hypo mice, GS labeling is present throughout the whole retina. (G) KO control animals reveal strong GS labeling throughout the retina. (H) Hypoperfused KO mice display GS labeling throughout the retina. Scale bars = 50 μm.