Figure 5. Organ culturing alters the potassium conductance of Müller glial cells and the retinal immunolabeling of Kir4.1 protein. Retinal tissues from wild-type (Wt) and A₁AR^−/− mice were used. The tissues were freshly isolated or derived from retinal organ cultures. A: Shown are examples of original records of whole-cell potassium currents, which were obtained in isolated Müller cells. Outward (upwardly depicted) and inward (downwardly depicted) currents were evoked by 20 mV incremental voltage steps up to +20 and −180 mV from a holding potential of −80 mV. The lines at left of each trace indicate zero current levels. B: Retinal organ culturing results in a decrease of the mean amplitude of the Kir currents of Müller cells. C: Retinal organ culturing results in a slight decrease in the mean resting membrane potential of Müller cells from A₁AR^−/− mice. D: Retinal organ culturing results in a decrease in the intensity of the Kir4.1 immunoreactivity. The arrows indicate perivascular staining, and the arrowheads point to the limiting membranes of the retina. Abbreviations: ganglion cell layer (GCL); inner nuclear layer (INL); inner plexiform layer (IPL); outer nuclear layer (ONL); outer plexiform layer (OPL); photoreceptor segments (PRS). Scale bars equal to 20 µm. The bar diagrams display mean (±SD) values obtained in 6–22 cells. Significant differences versus the respective control obtained in freshly isolated cells (the double closed circles indicate a p<0.01 and the triple closed circles indicate a p<0.001).