The left cerebral hemisphere was used for a wide range of biochemical and molecular biological studies. Left-hemisphere specimens from each brain were taken from the following neocortical regions at the time of autopsy: frontal pole (Brodmann area 10), middle frontal gyrus (MFG) (area 9), middle temporal gyrus (MTG) (areas 21 and 22), inferior parietal lobule (IPL) (areas 39 and 40), occipital lobe (areas 17 and 18), anterior cingulate gyrus (area 24), and posterior cingulate gyrus (PCG) (area 23). Specimens were also taken from the hippocampus at the level of the lateral geniculate nucleus, entorhinal cortex, amygdala, basal ganglia, nucleus basalis of Meynert, thalamus, midbrain, pons, medulla, and cerebellum. All of the specimens were immediately fixed in 4% formaldehyde. Most of the described specimens were also taken from the right hemisphere. All of the specimens were processed in the standard manner, and sections were cut at 8-μm thickness. Sections were stained with hematoxylin-eosin and the modified Bielschowsky method. The Gallyas stain was used on sections of the entorhinal cortex, hippocampus, and amygdala. All of the sections of cortical and ventromedial temporal lobe structures were immunostained with 10D-5 for β-amyloid peptide, and the amygdala, medulla, and olfactory bulb were used for α-synuclein immunohistochemistry using standard immunostaining methods. If Lewy bodies or Lewy neurites were found in any of these sections or in the midbrain or pons, α-synuclein immunostaining was carried out on neocortical, entorhinal, and hippocampal sections. Braak and Braak staging36,37 was performed using the Gallyas stain on ventromedial temporal lobe structures and Bielschowsky-stained neocortical sections. If argyrophilic grains (AGs) were found with the Gallyas stain in ventromedial temporal lobe structures, this stain was then carried out on the ambient gyrus, insula, gyrus rectus, and anterior cingulate gyrus to search for AGs.