Figure 5.

Confocal images of the double-fluorescence immunohistochemical study of microglia with IBA1 (green) (A and E) and MHC2 (red) (B and F). Representative images from a nondemented subject (A–D) and an AD patient (E–H) are shown. Also shown are merged high-power images from two different nondemented individuals (I and J) and from two different AD patients (K and L). Thioflavin-S staining (blue-green) identifies plaques (G, H, K, and L). The uniform morphology and labeling of microglia in nondemented subjects contrasts with the morphological and molecular diversity of microglia in AD. Three subpopulations of microglial cells are discernible with this double labeling: IBA1⁺MHC2⁻ (arrows), IBA1⁺MHC2⁺ (arrowheads), and IBA1⁻MHC2⁺ (double arrowheads) cells. Scale bars: 50 μm (A–H); 20 μm (K and L); 10 μm (I and J).