Figure 2

Morphological characterization of vascular (arteriolar) BACE1 and 6E10 immunoreactivity (IR) in postmortem human temporal neocortex. Panels (A,B) show selective BACE1 labeling at cortical vasculature visualized by collagen IV. Panels (C) illustrates BACE1 IR at a cross-sectioned arteriole, localizing to the tunica interna (TI) and around the tunica adventitia (TA) or the perivascular area, but not in the tunica media (TM). Panel (D) shows a feather-like pattern of BACE1 IR along a longitudinally cut intracortical arteriole. Panels (E-H) illustrate variable patterns of BACE1 IR among labeled (F-H) relative to unlabeled (E) arterioles in immunohistochemical preparation with hematoxylin and eosin stain (H.E.) counterstain. Arrows points to BACE1 IR in the TI (C,F), TA (C,D) and TM (G,H). Loss of cells in the vascular wall is noticeable in (G) and (H) relative to (E) and (F). The BACE1 IR in the TA and TM appears process-like (C,D,G,H). Panels (I-L) illustrate variable patterns of Aβ labeling at arterioles, with Aβ IR occurs primarily at the TI (I) or in the TM (J-L). Perivascular Aβ IR (arrows) often co-exists among the profiles with Aβ deposition in the TM with varying intensity (J-L), and appears segmentally in longitudinal view of the labeled vessel (M). Scale bar = 500 μm in (A) applying for (B); equal to 200 μm for (M) and 100 μm for other panels.