(B) Drp1-KO MEFs carrying Su9-GFP were treated with DMSO (control) or 10 nM antimycin A or 10 ng/ml oligomycin for 1 h and viewed by laser scanning confocal microscopy for 30 min with 10-s intervals in the presence of TMRE. The arrows indicate mitochondria that showed flickering. Three frames from the time-lapse analysis are shown (please also see Movie EV1-EV4). Scale bar, 10 µm. 