SYN1 and Alzheimer disease: Similarly, in the hippocampus of 16-month-old APP-PS1 C3 KO mice, levels of synaptic proteins (synapsin-1, synaptophysin, GluR1, PSD95 and Homer1) and pre- and post-synaptic puncta density (in the CA3 specifically, measured using staining for VGlut2 and GluR1, respectively) increased compared to APP-PS1 mice [140], highlighting the astrocytic impact on synaptic loss in AD pathology.