MAPT and Alzheimer disease: According to Braak et al. (2011) and Braak and Del Tredici (2012, 2013), abnormal p-Tau-os in non-fibrillar form were seen within proximal axons and AT-8 antibody-positive pre-tangles were observed within the somata and dendrites of projection neurons of brainstem locus coeruleus/ subcoeruleus of young boys well before they became manifest in the hippocampal trans-entorhinal region, the putative site of AD onset (Khan et al., 2014).