Figure 4. Coimmunostaining of P3 foveal glial cells with the Müller cell marker CRALBP, GFAP, and vimentin. Coimmunostaining of foveal cryosections from P3 with cellular retinaldehyde-binding protein (CRALBP), which is a specific marker of Müller cells in humans, glial fibrillar acidic protein (GFAP), and vimentin (VIM), which stains all glial origin cells, shows that the GFAP-positive cells at the roof of the foveal pit (A, B, C, D, and inset) are stained with vimentin (G, H, and inset) but do not express CRALBP (E, F, and inset). I: Costaining with GFAP and vimentin shows that the GFAP-positive cells at the roof of the pit (arrow) are faintly stained with vimentin and are distinct from the vimentin-positive Müller glial cell extensions (red arrow). GCL, ganglion cell layer; INL, inner nuclear layer; ONL, outer nuclear layer; HL, Henle’s fiber layer; OLM, outer limiting membrane.