Figure 5. GFAP processes sprout into the inner retina in CKO animals.

Whole CTL retina immunostained with GFAP (a). Schematic of retinal section showing that GFAP-positive astrocytic processes are almost exclusively confined to the NFL (green box, b). GFAP staining is uniform across the NFL when viewing a field en face (c, magnified from white box in a). The GCL and IPL are largely devoid of GFAP labeling in CTL retinas (d). Whole CKO retina stained with GFAP (e). Schematic of retinal section depicts GFAP-positive processes extending into the retina past the GCL (purple box, f). GFAP staining is uniform across the NFL in this example, as in CTL retinas (g), yet CKO retinas display sprouting of processes well beyond the level of their normal positioning (h, magnified from white box in e). Sprouting is extensive in the CKO retinas relative to CTL retinas (i, dashed line represents CTL retinas normalized to 1; CTL: n = 8, CKO: n = 9). High magnification z-stack reconstruction from CTL retina showing no astrocytic labeling extending into the inner retina (j). High magnification z-stack reconstruction from CKO retina showing aberrant sprouting into the inner retina extending at least 120 μm deep (k). Scale bar a,e = 1 mm; c,d,g,h = 100 μm, j,k = 25 μm. * = p ≤ .05.