FIGURE 4.

Localized transient depolarizations of ΔΨ_m. A and C show a selection of images taken of two cells. Each image shows one plane of a three-dimensional image stack. The arrows point to mitochondria in which changes in ΔΨ_m were observed during the image sequence. A decrease in FI denotes mitochondrial depolarization. Scale bars are 5 μm. B and D are a graphical representation of the FI (on a log scale) of the mitochondria indicated in A and C. The arrows above the traces indicate the time points for which images are shown. The scale bar on the right shows the change in ΔΨ_m (mV). Flickers vary in amplitude, frequency, time to depolarize, and duration of depolarization.