Fig. 3

Parenchymal interactions of typical astrocytes and shape descriptors in the stratum lacunosum-moleculare. Representative 5 nm per pixel of resolution scanning electron microscopy images acquired in the ventral hippocampus CA1 stratum lacunosum-moleculare of 20-month-old C57BL/6J male mice (A) and APP-PS1 male mice far (B) and near (C) Aß plaques/dystrophic neurites. Quantitative graphs represent the number of direct contacts with dendritic spines (D) per genotype (APP-PS1 vs C57BL/6J), and contacts with dendritic spines (E) and with synaptic elements (F) when spatially separating astrocytes between locations near vs far Aß plaques/dystrophic neurites. Quantitative graphs represent the shape descriptors of the astrocytic cell bodies, including G cytoplasmic area, H nucleus area, I cytoplasmic perimeter, and J nucleus perimeter. Data are shown as individual dots and are expressed as means ± S.E.M. *p < 0.05, **p < 0.01, using a non-parametric Mann–Whitney test for the comparison of dendritic spines in D, and a Kruskal–Wallis test with a Dunn’s post hoc for all other graphs shown. Statistical tests were performed on n = 8–12 astrocytes per animal in N = 3 mice/group, for a total of 102 cell bodies analyzed. red outline = plasma membrane, yellow outline = nuclear membrane, blue pseudo-coloring = axon terminals, orange pseudo-coloring = dendritic spines