[Figure 4].

Exercise-induced changes in microvascular pO₂ across cortical layers in old mice. (a) Capillary mean-pO₂ across cortical layers in sedentary controls and exercising mice. (b) Histograms of capillary pO₂ in layers I, II/III, and IV. (c) The mean Hct levels from sedentary (n=8) and exercise group (n=5). (d) and (e) Intravascular pO₂ and SO₂ in the diving arterioles across cortical layers I-IV in sedentary (blue boxplots) and exercise (red boxplots) group, respectively. (f) and (g) Intravascular pO₂ and SO₂ in the surfacing venules across cortical layers I-IV in sedentary (blue boxplots) and exercise (red boxplots) group, respectively. (h) Depth-dependent OEF in sedentary (blue boxplots) and exercise (red boxplots) group. The analysis in (a) and (b) was made with 1224, 2601, and 922 capillaries across n=9 mice in sedentary group and 1334, 2840, and 1078 capillaries across n=9 mice in exercise group in cortical layers, I, II/III, and IV, respectively. The analysis in (d-h) was made with 13 arterioles and 12 venules from n=9 mice in sedentary group and 14 arterioles and 12 venules from n=9 mice in exercise group. Statistical analysis was carried out using Two-way ANOVA with post hoc Tukey’s in (a) and (d-h) and Student’s t-test in (f). *p<0.05; **p<0.01. Additional details on boxplots and exclusions are provided in the Supplementary document.