MAPT and Alzheimer disease: A recent optical superresolution study using expansion microscopy showed tau oligomers in synapses, and tau oligomer–tagged synapses engulfed by microglia, the CNS-resident macrophages, and also by astrocytes in necropsy tissue of AD patients, with substantial loss of presynaptic (43%) and postsynaptic (38%) structures (Taddei et al., 2023).