Ex vivo quantitative amyloid and perivascular space measurements in white and gray matter on immunohistological microscopy in AD, MCI, and cognitively intact individuals

Amyloid (Aβ) clearance is disturbed in late‐onset Alzheimer’s disease (AD), and a local relationship between Aβ clearance and gray (GM) and white matter (WM) perivascular spaces (PVS) is presumed. Most in vivo primate work has focused on MRI‐visible PVS in WM, described as pathological and enlarged, while nearly all in vivo mechanistic work in animals interrogates “normal” GM PVS. This disparity describes a critical knowledge gap in the morphology, location and relevance of PVS to Aβ clearance.