MAPT and Alzheimer disease: For these studies, fixed contiguous serial sections from the striatum (CBD and PSP samples), the frontal cortex (PiD sample) and the pons (PSP sample) were either immunostained with a polyclonal tau antibody for the detection of tau lesions or incubated with the fluorescent compound THK523 to determine whether THK523 bound to non-AD tauopathy aggregates.