A: HSD tends to reduce body weight and increase caloric intake, but the effect is not statistically significant; Diet: p = 0.2668, Time: p < 0.0001; ND/HSD n = 15/20 mice/group (Two-way ANOVA and Tukey’s test). B: HSD does not alter systolic blood pressure measured in awake animals by tail-cuff plethysmography. Diet: p = 0.9417, Time: p = 0.1382; ND/HSD n = 15 mice/group (Repeated two-way ANOVA and Bonferroni's test). C: HSD does not alter the CBF response to the smooth muscle relaxant adenosine; Diet: p = 0.9659, Time: p = 0.0549; 4 weeks: ND/HSD n = 8/5; 8 weeks: ND/HSD n = 10; 12 weeks: ND/HSD n = 10/8; 24 weeks: ND/HSD n = 7 mice/group (Two-way ANOVA and Tukey's test). D: HSD reduces resting CBF in the hippocampus. * p = 0.0245 vs. 0 weeks; 0 weeks n = 8, 12 weeks n = 7, 24 weeks n = 5 mice/group (One way ANOVA and Tukey’s test). E: Temporal profile of CBF increase induced by whisker stimulation after 4, 8 and 24 weeks of ND or HSD; 4 weeks: ND/HSD n = 7/7; 8 weeks: ND/HSD n = 6/7; 12 weeks: ND/HSD n = 9; 24 weeks: ND/HSD n = 5/7 mice/group. The dotted line indicates the baseline CBF whereas the shaded area represents the standard error. F: CBF increase to whisker stimulation assessed as area under the curve shows a diet effect (Diet: p = 0.0013, Time: p = 0.6687), which did not reach statistical significance at the Tukey’s test; 4 weeks: ND/HSD n = 7/7; 8 weeks: ND/HSD n = 6/7; 12 weeks: ND/HSD n = 9; 24 weeks: ND/HSD n = 5/7 mice/group (Two-way ANOVA and Tukey's test). G: Return to normal diet does not alter MAP and CBF responses to whisker stimulation and adenosine. MAP: p = 0.2406; Whisker: p = 0.2340; Adenosine: p = 0.8010, n = 5 mice/group (One-way ANOVA and Tukey’s test). H: Endothelial dysfunction is also observed in mice fed a 4% HSD for 12 weeks. ACh: * p < 0.0376 vs ND; ND/HSD n = 4/5 mice/group (unpaired t-test, two-tailed). I: A 4% HSD impairs performance at the novel object test (p = 0.0350 vs ND, unpaired t-test, two tailed). J: Resting NO production, assessed by DAF-FM, is reduced in pial microvascular preparation from mice fed a HSD. The effect is reversed by administration of the NO precursor L-arginine. * p = 0.0024; microvessels isolated from 8 (ND Veh), 6 (ND L-Arg), 7 (HSD Veh) and 9 (HSD L-Arg) mice/group (One-way ANOVA and Tukey’s test). Data are expressed as mean ± SEM.