Figure 8. Analysis of single confocal optical sections indicated that Na_v1.1 labeling is present in multiple locations in the outer plexiform layer

A-C: Confocal microscopy of double labeling for Na_v1.1 and calbindin at the level of the OPL in retinal wholemount confirmed that little Na_v1.1 labeling was present in the tips of horizontal cell dendrites (labeled for calbindin; arrowheads). A single optical section is shown. D-F: Labeling for Na_v1.1 and VGluT1 co-stratifies in the OPL, suggesting some Na_v1.1 labeling was associated with photoreceptor terminals. However, a substantial amount of Na_v1.1 labeling did not colocalize with VGluT1 labeled photoreceptor terminals (arrowheads). Labeling of blood vessels (bv) was non-specific. A single confocal optical section shown. G-I: Only limited colocalization of Na_v1.1 and mGluR6 labeling on the dendritic tips of ON bipolar cells is present in the OPL (arrows). Although most mGluR6-positive puncta did not show colocalization with Na_v1.1 (arrowheads), labeling for Na_v1.1 and mGluR6 were found in close proximity. A single confocal optical section is shown. The following abbreviations were used: outer nuclear layer (ONL); inner nuclear layer (INL). Scale bars equal 5 μm for A-C; 10 μm for D-I.