F, Average ΔF/F0 SyGCaMP5 traces for 80 stimuli (n=7 neurons, 21 terminals, t= 20-28s, ΔF/F0 = 1.3 0.2 with and 2.2 0.5 without mitochondria, paired t-test, *p<0.05), 40 stimuli (n=5 neurons, 25 terminals, t= 20-24s, ΔF/F0 = 0.9 0.3 with and 2.0 0.4 without mitochondria, paired t-test, *p<0.05), 20 stimuli (n=10 neurons, 55 terminals, t= 20-22s, ΔF/F0 = 0.8 0.4 with and 1.8 0.4 without mitochondria, paired t-test, *p<0.05) and 10 stimuli (n=4 neurons, 21 terminals, t= 20-21s, ΔF/F0 = 0.4 0.3 with and 0.4 0.1 without mitochondria, paired t-test, p=0.90), all delivered at 10 Hz. Experiments performed in E18 or P0 rat hippocampal neuronal cultures at DIV 10-12. Error bars represent SEM. 