Figure 2
From: Mitochondrial redox and pH signaling occurs in axonal and synaptic organelle clusters
Parallel assessment of redox and pH dynamics of entire mitochondrial populations.
Grid analysis allows readout of signal traces of single mitochondria exhibiting no signal changes, single, double and multiple/permanent oxidations in a representative axon (a). In the bottom image single event-mitochondria are shown with black overlay, double events with red overlay, multiple events with blue overlay and no events have no overlay. Mitochondrial matrix pH dynamics are assessed in AAV-mito-SypHer explants. Single, double and multiple pH spikes are found in individual mitochondria. Representative single traces are shown in (c). Single oxidation (black trace) compared to multiple oxidation traces (blue trace, d). n = 47 single oxidations and n = 35 multiple oxidations. Signal amplitudes in single and multiple event-mitochondria. EGSH and pH amplitudes are shown (e). Mean mitochondrial area of event-mitochondria. Larger mitochondria are more likely to show redox or pH spikes (f). Differences in mitochondrial sizes might be due to the different techniques of fluorescent sensor expression (Grx1-roGFP2: transgenesis; SypHer: viral particles). Frequency of successive mitochondrial EGSH and pH events (g,h). A subpopulation of mitochondria shows a scaling behavior of the SypHer signal (i). Scale bar in a = 5 μm. *p < 0.05, **p < 0.01, ***p < 0.001.
