SYP and Alzheimer disease: We imaged five confirmed AD (Braak V–VI) and five age/sex-matched control cases (Braak 0–III) for p-tau Ser356, AT8 (tau phosphorylated at Ser202 and Thr205) and the pre-synaptic marker synaptophysin (Fig. 3a–e) or post-synaptic marker PSD95 (Fig. 3f–j).