To quantify synapse loss, we labeled presynaptic and postsynaptic compartments in the dentate gyrus of 6-mo-old App/Ps1-/- and App/Ps1+/- littermates by detecting synaptic vesicle protein 2 (SV2) and Homer1, respectively, and selected multiple fields of interest per animal for imaging analysis while avoiding regions adjacent to amyloid deposits (Figure 7—figure supplement 2). Here, PSEN1 is linked to amyloidosis.