Fig. 6From: Sodium channels enable fast electrical signaling and regulate phagocytosis in the retinal pigment epitheliumPOS phagocytosis assay of shRNA Nav1.4 silenced hESC-derived RPE. Whole-cell patch clamp recordings were performed on mature hESC-derived RPE monolayers as responses to a series of depolarizing voltage pulses (− 80 to + 60 mV) after strong hyperpolarization a from control RPE cells, control vector cells (EGFP) and cells where Nav1.4 had been silenced with lentiviral vectors encoding shRNAs. The average current–voltage relationship (mean ± SEM,) was plotted for b Control hESC-derived RPE (n = 4), c EGFP expressing cells (n = 3), and d shRNA expressing cells (n = 3) (individual datapoints for b-d available in Additional file 8: Table S3). e The level of POS phagocytosis was analyzed with the EGFP expressing hESC-derived RPE cells. Filamentous actin was stained with phalloidin (blue) to highlight epithelial cell-cell junctions, EGFP (red) was used to identify the transduced cells and POS were labeled with opsin (green). f The average distribution of POS particles was analyzed from several images that had a single shRNA expressing cell placed in the middle. g The relative intensity of POS labeling in each square of the 3 × 3 grid was analyzed from Nav1.4 shRNA cells (n = 22 images) and control EGFP cells (n = 18 images). Scale bars 10 μmBack to article page