Fig. 9

Blood vessel-associated dark astrocyte in the stratum lacunosum-moleculare. Representative 5 nm per pixel of resolution scanning electron microscopy images of dark astrocytes acquired in the ventral hippocampus CA1 stratum lacunosum-moleculare of 20-month-old APP-PS1 male mice. In A–A″, a dark astrocyte associated with the vasculature (pseudo-colored in red) is directly interacting with a typical microglial cell body. The red arrows in A″ further indicate the close interaction between the two glial cells. Dark blue outline = dark astrocytic cytoplasm, light blue outline = microglial cytoplasm, yellow = nuclear membrane, red pseudo-coloring = blood vessel, red arrow = direct interaction between a microglial cell body and a dark astrocyte