Fig. (1) AT8-positive neurofibrillary tangle is noted in the locus ceruleus (1A - left). Some degree of τ pathology was present in the locus ceruleus in all subjects, in only one immunostain of a 6 micron thick section. No Aβ was present in the locus ceruleus region in any of the cases (1B - right). Scale bars = 30 μm.