MAPT and Alzheimer disease: In bipartite synapses of AD subjects (Figure 4B), immunostaining with Alz-50 antibody detected misfolded tau at both presynaptic and postsynaptic terminals, and the distribution ratio was 15.4%:16.4%:2.9% (presynaptic-only/postsynaptic-only/both), showing bilateral symmetry across the synaptic cleft.