Extended Data Fig. 3: Reduction in vascular length and pericyte cell density in layer 6/CC of aged mice.
a. Maximum intensity projection of the dorsal half of a whole mouse brain with arterioles labeled using α-SMA + Sm22 immunostaining imaged by light-sheet microscopy. b-d. Top-down views of the 540 × 540 × 1000 µm (x, y, z) regions of interest (ROI) centered on the somatosensory cortex marked with a dotted yellow square in (a), with arterioles labeled using α-SMA + Sm22 antibodies (b), all vessels labeled using fluorescent lectin (c), and mural cells labeled using the combination of anti-PDGFRβ and anti-CD13 antibodies (d). e,f. 3D side views from Imaris showing lectin (e) and mural cell (f) staining throughout the entire cortical depth. g, h. Examples of 200 µm thick ROIs from (e) and (f) (marked with dotted yellow lines) with reconstructions of all capillary segments (g, gray lines)) and annotated capillary pericyte cell somata (h, blue circles). i. Top-down view of vessels (cyan) and mural cells (red). j. Magnified regions from (i) (marked with yellow squares) with annotated examples of capillary pericytes exhibiting the ‘bump on the log’ morphology (marked with yellow arrows). k. Vascular length density in analyzed cortical subsections of adult and aged mice. Two-sided unpaired t-tests: 0–200 µm, p = 0.3849; 201–400 µm, p = 0.0541; 401–600 µm, p = 0.0005; 601–800 µm, p = 0.0034; 801–1000 µm, p = 0.0006. l. Pericyte density in analyzed cortical subsections of adult and aged mice. Two-sided unpaired t-tests: 0–200 µm, p = 0.7185; 201–400 µm, p = 0.2007; 401–600 µm, p = 0.0418; 601–800 µm, p = 0.0134; 801–1000 µm, p = 0.0038. m. Pericyte density in analyzed cortical subsections of adult and aged mice. Two-sided unpaired t-tests: 0–200 µm, p = 0.8617; 201–400 µm, p = 0.8043; 401–600 µm, p = 0.8913; 601–800 µm, p = 0.6062; 801–1000 µm, p = 0.0376. For all plots in k-m, n = 4 animals per age group. Data shown as mean ± SEM.
