Amyloid and tau in the brain in sporadic Alzheimer’s disease: defining the chicken and the egg

In the October 2013 issue of iActa Neuropathologica/i there were three very interesting articles on: iAmyloid or tau: the chicken or the egg?/i In the first article, David Mann and John Hardy argued that the deposition of aggregated amyloid β (Aβ) protein in the brain is a primary driving force behind the pathogenesis of Alzheimer’s disease with tau pathology following as a consequential or at least a secondary event. In the communication that followed, Braak and Del Tredici presented the contrary argument with accumulation of tau protein as the primary event in sporadic Alzheimer’s disease. Attems and Jellinger questioned the concept of a chicken and egg and suggested that the majority of cases of age-associated dementia are not caused by one single primary pathological mechanism.