D E, However, there is no significant difference in the presynaptic Ca2+ response in terminals with and without a mitochondrion in response to single action potentials. D, Example trace of hippocampal neurons transfected with MtDsRed and SyGCaMP5. 1 ms stimulation pulses were applied every 5 s. The red trace represents an average of the terminals occupied with a mitochondrion in this neuron, whereas the black trace represents the averaged response of terminals without a mitochondrion. E, Maximal fluorescence intensity in terminals without a mitochondrion (left) or with a mitochondrion (right) within the same axon (dots connected by a line) (n=8 neurons, 44 terminals, paired t-test, p=0.55). 