Example images showing the extent of neuronal T49-positive tau aggregates in wells treated with AD-tau versus those that were not seeded are shown in Figure 1D, as are parallel AD-tau seeded and non-seeded cultures that were fixed and permeabilized followed by staining with NeuN (34) and MAP2 (35) antibodies to assess the number of neuronal cells and the dendritic process area, respectively. Here, MAPT is linked to Alzheimer disease.