Figure 8: Photomicrographs showing AT8 immunoreactivity in the cortex ((a)–(c)), ventral CA1, ((d)–(f)), BLA ((g)–(i)), and subiculum ((j)–(o)) in 3-week, 9-, and 18–20-month-old 3xTg-AD mice. Transcardially fixed tissue revealed more AT8-ir neurons in the ventral hippocampus than either the neocortex or BLA in 3-week-old 3xTg-AD mice ((a), (d), (g)). Note that AT8-ir neurons within the hippocampus appeared shrunken with blunted dendrites at 9 months of age (e) when compared to younger (d) mutant mice. AT8 immunoreactive dystrophic neurons and plaques were observed in the subiculum of both male and female 20-month-old 3xTg-AD mice ((j)–(o)). Note the dystrophic neuronal morphology in male (k, arrow) and female (n, arrow) mice as well as the extent of tau pathology ((j), (m)). Dash line in m demarcates the boundary between the CA1 field and the subiculum. (l) and (o) represent higher magnification of boxed areas (j) and (m) respectively. Ntg 3-week-old mice displayed virtually no AT8 immunoreactivity ((c), (f), (i)). Scale bars: ((a)–(i)); ((k), (l), (n), (o)) = 20  m and (j), (m) = 100  m.