Angiogenesis, not apoptosis, induces alterations in blood–brain barrier (BBB) permeability in Alzheimer’s disease (AD). Representative confocal micrographs of tight junctions (TJ). Hippocampal sections from aged wild-type and Tg2576 AD model mice are stained with either (A) Occludin (red) or (B) ZO-1 (red), and double-stained for CD105 (green), a known marker of angiogenesis. All vessels stained for CD105 regardless of the TJ expression pattern. Scale bar represents 20 μm. (C) Aged Tg2576 mice had significantly increased CD105 protein levels in the hippocampus compared with age-matched wild-type mice (n = 7, *P <0.05). (D) The hippocampus of the AD patient had a significantly increased microvascular density (MVD), as measured by percentage area occupied by laminin staining, compared with the ND (no disease) patient (n = 4, ***P <0.001). Representative images of immunohistochemical staining for laminin in the cortex of the ND patient (E) and the AD patient (F). Scale bar represents 95 μm. Values represent mean ± standard error of the mean. Adapted from .