Fig. 1

Parenchymal interactions of typical astrocytes in the stratum radiatum. Representative 5 nm per pixel of resolution scanning electron microscopy images acquired in the ventral hippocampus CA1 stratum radiatum of 20-month-old APP-PS1 (far from Aß plaques/dystrophic neurites) and age-matched C57BL/6J male mice (A, B). Quantitative graphs represent the number of direct contacts with C all synaptic elements, D axon terminals, E dendritic spines, and F both elements of the same synapse (axon terminals and dendritic spines). In G and H, the graphs represent, respectively, the area and perimeter of the astrocytic cell body. Data are shown as individual dots and are expressed as mean ± S.E.M. *p < 0.05, using a non-parametric Mann–Whitney test. Statistical tests were performed on n = 8–11 astrocytes per animal in N = 3 mice/group, for a total of 59 cell bodies analyzed. red outline = plasma membrane, yellow outline = nuclear membrane, orange pseudo-coloring = dendritic spine, blue pseudo-coloring = axon terminals