Using high-resolution array tomography on post-mortem temporal and occipital cortices of AD patients, it was found recently that phosphorylated or misfolded tau, but mostly oligomeric tau accumulates in both pre- and post-synaptic terminals of the same synapses (Colom-Cadena et al., 2023), suggesting that oligomeric tau could be the main species of tau that spreads trans-synaptically. Here, MAPT is linked to Alzheimer disease.