MAPT and Alzheimer disease: Therefore, it remains possible that neurons of LC (as well as others such as those in DRN and nucleus of Meynert) are exquisitely vulnerable to a range of physiological or neurotoxic changes that induce tau pathology, and that these putative early changes in tau in LC in healthy young people in the absence of amyloid deposits [6, 8] might simply be serendipitous or even transient, never progressing into a pathological process culminating in AD.