FIGURE 6.

ΔΨ_m flickering at nonquenching TMRM loading conditions in the presence of TFP, 2-APB, and propranolol. Image pairs show raw TMRM fluorescence (top) and electrical syncytia (bottom). Individual electrical syncytia where TMRM fluorescence fluctuating synchronously were assigned to different colors and visualized by uniform coloring of those areas within the shaded silhouette of mitochondria. Colored ellipses indicate the extension of a few selected syncytia. (A) Control (typical of n = 22 cells); (B) TFP (10 μM; n = 14); (C) 2-APB (50 μM; n = 15); (D) propranolol (50 μM; n = 14). Drugs were applied using a 20-min preincubation, and were continuously present during the experiment. The image series corresponding to A is available as Supplementary movie 3.