Fig. 3
High fat diet induces microglia activation in males but suppresses it in females. Microglia were labeled using Iba1 (cyan) and CD68 (magenta). Cells were classified into 4 groups depending on morphology and CD68 immunoreactivity: ramified cells with or without CD68 and ameboid cells with or without CD68 (A, i–iv). Scale bar 20 µm. The % area occupied by the Iba1 labeling was quantified in the CC (B) and the hippocampus (H). Cell densities were quantified in the corpus callosum (C–E) and the CA1 region of the hippocampus (I–K). Data are represented as mean + SEM. 2-way ANOVA with Tukey’s post hoc test. #p < 0.05 effect of VCID; *p < 0.05, **p < 0.01 effect of diet. 3-way ANOVA results are reported under the graph *p < 0.05, **p < 0.01, ***p < 0.001. Correlation of Iba1+ ameboid cell density with body weight change expressed as % of body weight at the start of the experiment in the CC (F) and in the CA1 of the hippocampus (L). Correlation of ameboid Iba1+CD68+ cell density with the novel object recognition index (NORI) as a measure of episodic-like memory in the CC (G) and in the CA1 of the hippocampus (M). Correlation analyzed using simple linear regression for each sex with r2 and p values noted for each. *p < 0.05, ***p < 0.001, n = 4–6 mice/group. Ctrl  control diet, HFD high fat diet