Fig. 4

Subcellular compartmentalization of ROAs in human microglia. A Left: 4D average intensity projection (24 µm depth) of a mCyRFP1-CaNeon-expressing ramified microglial cell alone (upper panel) and with the overlayed sample ROAs, shown in different colors (lower panel). Right: spontaneous ongoing Ca²⁺ signals (asterisks) recorded from ROAs, labeled with the respective number in the lower left panel. B Pie charts showing the spatial distribution of ROAs in ramified (left panel), hypertrophic (middle panel), and amoeboid (right panel) microglia. C Box plots showing the morphotype-specific distributions of ROA areas. ROAs were significantly smaller in ramified compared to amoeboid microglia (P = 10^–3; here and below: the Kruskal–Wallis test followed by the Holm-Bonferroni post hoc test for multiple comparisons). D Box plots illustrating the frequencies per cell of Ca²⁺ transients in ramified, hypertrophic and ameboid microglia (n = 31, 20, 5 cells, respectively). E Schematic, defining the parameters of Ca²⁺ transients analyzed in this study. F–H Box plots showing amplitudes (F; P = 3.4*10^–4 and 0.02 for comparison of ramified to hypertrophic and hypertrophic to ameboid microglia, respectively), FWHM (G; P = 8.7*10^–3 for comparison of ramified to hypertrophic microglia) and AUC (H; P = 3.3*10^–3 for comparison of ramified to hypertrophic microglia) of Ca²⁺ transients for microglia of different morphologies