Fig. 1

Amyloid beta and tau deposition in the 36-year-old monkey. Double staining for PHF tau (AT8, dark purple or black) and Aβ (brown) in brain slices from the 36-year-old monkey a. Pyramidal neurons were positive for AT8 (arrow, a). Higher magnification of a temporal lobe region, indicated by the large rectangle in a, is shown in b, again showing AT8-positive neurons in dark purple, and Aβ-positive deposits in brown. AT8 immunoreactivity (IR) was abundant in the globus pallidus (arrowhead in a) and in the white matter of the hippocampus (asterisk in a and d). In higher magnification images of the globus pallidus c, AT8 IR was found along fiber bundles (asterisk) and small round cells (arrowheads. See Fig. 4 for more details). Brown deposits are macrophages containing hemosiderin. Higher magnification of the hippocampal white matter (asterisk d and e) revealed AT8-positive oligodendroglia-like cells (arrowheads in e) and fibers (asterisks in e). The hippocampal white matter (asterisk, f) and pyramidal neurons (arrow, f) were also immunopositive with RD4 (dark purple staining in f) but not for RD3 (data not shown). Images (a–f) were captured using a virtual slide system VS120 (Olympus, Tokyo, Japan), equipped with “extended focus imaging”. Multiple images at different focal planes (17 planes with an interval of 0.5 μm) were fused into a single image. a–c, e: double staining for AT8 (dark purple) and Aβ (brown); d: Klüver-Barrera stain; f: RD4 immunostaining counter stained with nuclear fast red. Bars a:5 mm; b:200 μm, c:100 μm; d, f:1 mm, e:20 μm