Confocal analysis of AII amacrine cells counterstained with antibodies to Cx36. AII amacrine cells injected with Neurobiotin and visualized with FITC show their typical morphology in vertical slices of both Cx36 −/− and Cx36 +/+ animals.A and C represent 200 nm optical sections of Cx36 −/− and Cx36 +/+ mice, respectively. When double-labeled with antibodies to Cx36, only wild-type mice display significant overlap in the dendritic region of AII cells (C,arrows). In B and D, a stack of superimposed optical sections is displayed to show the overall morphology of AII amacrine cells and the extent of double-labeling in the ON sublamina of the inner plexiform layer. Scale bars, 50 μm.