The decrease of 5-HT2 receptor densities in the caudate nucleus of PSP brains with moderate to severe tau pathology compared with those with mild tau pathology cannot be explained merely by a more severe neurodegeneration in the former group, because we did not observe an association between tau pathology and 5-HT2 receptor alterations in area 24′. Here, MAPT is linked to supranuclear palsy, progressive, 1.