Figure 14: Electron photomicrographs showing perinuclear and cytoplasmic 6E10 immunoreactivity (black arrows) in hippocampal/subicular complex neurons at 2- (a) and 9- (b) month-old 3xTg-AD mice. Micrographs showing scattered Alz50 (c) and AT8 (d) immunoreactivity in hippocampal/subicular complex neurons in 2-month-old 3xTg-AD mice, whereas at 9 months Alz50 (e) and AT8 (f) immunoreactivity was increased, without the formation of filaments as seen in AD (g). Boxed area shows a higher-magnification photograph of the morphology of paired helical filaments in the AD brain (h). Photomicrographs of Alz50 ((i) and (j)) and AT8-ir ((k)–(m)) filaments in hippocampal/subicular complex neurons at 23 months in the 3xTg-AD mouse. J, Panel shows detail of straight Alz50-ir filaments from the white boxed area in (i). (l) and (m) areas containing AT8-ir filaments are outlined in white in panel k showing AT8 positive filaments in cross (l) and longitudinal (m) profile. Abbreviation: n: nucleus. Scale bars in (a), (b), (g) =2  m, (c), (d), (f), (k) = 1  m, (e), (i), (h) = 0.5  m and (j), (l), (m) = 200 nm.