MAPT and early-onset autosomal dominant Alzheimer disease: To examine the seeded aggregation of α-syn in cultured cells, we prepared sarkosyl-insoluble fractions from 3 cases of MSA (cerebellum, frontal cortex and putamen), 4 cases of DLB (frontal cortex and temporal cortex), one case of Alzheimer’s disease (AD) and one control, and analyzed them by immunoblotting with PS129 and anti-tau antibody T46.