A–F, Sections of adult wild-type littermate (left column) and Nestin-CRE/DG-null (right column) retina labeled with antibodies to mGluR6 (A, B) and Kir4.1 (C–F). G, H, Sections of wild-type littermate (left column) and GFAP-CRE/DG-null (right column) retina labeled with an antibody to Kir4.1. Note the loss of Kir4.1 localization in perivascular glial endfeet (normal marked by asterisks in E, G) and the loss of Kir4.1 clustering in Müller glial endfeet at the inner limiting membrane (arrows). Müller glial processes (arrow heads) retained Kir4.1 expression. The sections were counterstained with propidium iodide. E, F, High-magnification views of the boxed regions in C and D, respectively. GCL, Ganglion cell layer; IPL, inner plexiform layer; INL, inner nuclear layer; OPL, outer plexiform layer; ONL, outer nuclear layer.