The two histopathological hallmarks that characterize Alzheimer s disease (AD) are the extracellular amyloid plaques that are formed by b-amyloid fragments of the amyloid precursor protein (APP), and intracellular neurofibrillary tangles and neuropil threads, which consist of the microtubule-associated protein tau forming paired helical filaments with highly ordered structures, as recently corr...
