Figure 1.

Astrocytic Endfeet Are Enriched in Mitochondria-ER Contact Sites

(A) Experimental design.

(B) Example of an astrocyte co-transduced with ER-GFP and mitoRFP viruses. Yellow arrowheads: endfeet. Scale bar, 10 μm.

(C) Magnifications of the astrocyte shown in (B). Yellow arrowheads point to bundles of elongated mitochondria. Scale bar, 5 μm.

(D and E) Example of astrocytes transduced with ER-GFP or mitoYFP (in gray) wrapping around dextran-labeled vessels (in red). Insets show zooms of the perivascular endfoot. Side panels: 3D rendering of the same astrocytes. Scale bars, 10 and 25 μm.

(F) EM picture of a vessel cross-section showing the astrocytic endfoot (segmented black line) and its organelles (mitochondria, yellow; ER, red; contact sites, blue). Inset: mitochondria-ER contact sites lining the basal lamina. Scale bars, 2 and 1 μm.

(G) Perisynaptic astrocytic processes and their organelles. Scale bar, 2 μm.

(H) Quantification of mitochondrial parameters in branches (n = 21 cross-sections from 3 mice) and endfeet (n = 32 cross-sections from 3 mice; nonparametric Mann-Whitney t test). ^∗∗∗p < 0.001. PC, pericyte; EC, endothelial cell; BL, basal lamina.

See also Figure S1.