MAPT and Alzheimer disease: The ultrastructure of the inclusions in PSP are straight filaments in tufted astrocytes, coiled bodies, and globose tangle inclusions, mainly consisting of 4R tau, in contrast to the paired helical filament structure of aggregates in neurofibrillary tangles of 3R and 4R tau in AD.22, 23 The autoradiographic findings of the present study are in line with recently published results showing an absence of19, 20 or minimal24 specific binding of the tracer AV‐1451 to tau aggregates in cortical postmortem samples from PSP cases.