FIGURE 8.

Comparison of sorfra plaques, β-amyloid, and pTau pathologies in adjacent sections of the primary motor cortex (PMC) in an AD brain with Thal phase 5 and Braak stage VI neuropathologies. Section orientation, figure panel arrangement, cortical lamination (I–VI), and scale bars are as indicated. For orientation, “sf” in (A) is the abbreviation of the cerebral sagittal fissure, with “M” and “L” in (B) indicating the medial and lateral directions relative to anatomical position. (A–E) Low- and high-power views of the distribution and morphology of sorfra plaques in area 4, including the medially located paracentral lobule (A–C) and the laterally located precentral gyrus (A,D,E). Labeled extracellular plaques, as well as neuronal somata, are present in the cortical gray matter of both subregions (B–E). (F–J) Aβ immunolabeling, which appears as densely packed compact and diffuse-like plaques over the superficial layers (I–III) of the cortex. Many compact plaques have an intensely labeled core (H,J, as pointed by arrows), whereas some large diffuse-like plaques also have core-like area with heavy immunolabeling (J, low-left). (K–O) BACE1-immunolabeled dystrophic neurites in both subregions of the PMC. At high magnification, some neuritic clusters consist of strongly labeled and densely packed dystrophic neurites, whereas other clusters contain loosely packed and lightly stained neuritic elements (M,O, as pointed by arrows). (P–T) The presence of pTau-immunoreactive neuronal somata and processes in both subregions of area 4. Phosphorylated tau-positive neurites are mostly present as fine processes, whereas some of them are apparently arranged as clusters (Q–T, as pointed by arrows). Phosphorylated tau-labeled neuronal somata often appear to be tangled by close examination (R,T, as pointed by arrowheads).