in apical arbors than in control (APP+/−) mice (Fig. 2A, B). Apical dendritic length was also shorter in old APP−/− mice compared to APP+/− mice, but no significant changes were seen in basal dendritic length (Table 1). Further analysis showed that CA1 neurons from old APP−/− mice showed significantly shorter apical lengths, specifically between 60 and 180 μm away from the soma (overall interaction F(11,110 ) = 1.76, p = 0.07; effect of genotype F(1, 10) = 5.21, p = 0.04, distance from soma F(11,110) = 79.46, p < 0.0001; Fig. S1A). Significant differences in Sholl analysis of basal dendritic length and number of intersections were also seen (overall interaction for Sholl and number of interaction respectively F(7,70) = 2.235, p = 0.003; F(7,70) = 2.78, p = 0.01; Fig. S1B). In contrast, young APP−/− animals (2-4 months old) did not show a reduction in the complexity of apical dendrites. Not surprisingly, there were no changes in both apical and basal dendritic length in young mice (Fig. 2E and F and Table 1). In addition, we examined whether there was an age-dependent reduction in dendritic length in control mice and found that CA1 neurons exhibited similar apical and basal dendritic
