Fig. 3: MDSs are characterized by different functional states.
a Representative image of mitochondria stained for Halo-OMM (magenta) and tetramethyl rhodamine ethyl ester (TMRE), a membrane potential indicator (green), inside a neuronal cell. MDSs are highlighted with dotted lines. Line profiles measured across #1, #2, and #3 for TMRE (green dots) and OMM (pink dots for the data points and pink line for the Gaussian fit) show their sizes and intensities. The image is a representative example of the data plotted in (d–g). b Four examples of MDSs stained for Halo-OMM (magenta) and TMRE (green): (top) two vesicles with membrane potential, and (bottom) one vesicle and one stick without membrane potential. The images are representative examples of the data plotted in (d–g). c Four examples of MDSs stained for Halo-OMM (magenta) and reactive oxygen species (ROS) indicator (MitoSOX) (green); (top) two vesicles showing an accumulation of ROS, and (bottom) a vesicle and a stick without ROS. The images are representative examples of the data plotted in (h–k). d Distribution of the area of the entire mitochondria population, divided into mitochondria with (green) and without (gray) TMRE signal. Data were collected from 9 DIV7 hippocampal neurons from four independent experiments. NTMRE+ = 238, NTMRE− = 90. Kolmogorov–Smirnov (KS) test, ****P < 0.0001 (P = 4.2 × 10−29). e, f Distribution of the area and aspect ratio of MDSs, divided into MDSs with (green) and without (gray) TMRE signal. NTMRE+ = 33, NTMRE− = 72. KS tests, ****P < 0.0001 (Parea = 2.6 × 10−7); Paspect ratio = 0.58. g The ratio of vesicles and sticks with (green) and without (gray) TMRE signal. h Distribution and ratio of the area of the entire mitochondria population, divided into mitochondria with (green) and without (gray) MitoSOX signal. Data were collected from four DIV7 hippocampal neurons from two independent experiments. NMitoSOX+ = 366, NMitoSOX− = 85. KS test: ****P < 0.0001 (p = 4.2 × 10−9). i, j Distribution of the area and aspect ratio of MDSs, divided into MDSs with (green) and without (gray) MitoSOX signal. NMitoSOX+ = 130, NMitoSOX− = 59. KS tests: Parea = 0.20; *P < 0.05 (Paspect ratio = 0.019). k The ratio of MDSs and sticks with (green) and without (gray) MitoSOX signal.
