(A–E) Microglia/monocytes (Iba1, red) expressing CD68 (green) are significantly increased in regions of plaques in the hippocampus (blue, ThioS) in B6.APBTg mice fed the western diet (B,E,D) compared to the control diet (A,C) (p = 0.0184, n = 4, E). Middle panels (C,D) show high-resolution images from the white boxes seen in top panels (A,B). Although images were captured using exactly the same parameters, there appears to be higher levels of background ThioS staining in tissue from WD mice (B,D) compared to control diet (A,C). (F) There is a strong correlation between the number of IBA1+ cells and amyloid-β plaque number in the hippocampus (p = 0.0007, R2 = 0.9583, n = 3). (G–I) Microglia/monocytes are significantly increased in the entorhinal cortex surrounding plaque in western diet-fed B6.APBTg mice (p = 0.0086, n = 4). Blue = DAPI. Scale bars: A,B,G,H = 160 μm; C,D = 40 μm.