Figure 4

Cerebral amyloid angiopathy and microhemorrhages in APP DSL mice. A. Cerebral blood vessels (green) in DSL mice start to accumulate Aβ (red) around middle age (9 ~ 10 month of age), and became more extensively covered by amyloid at old age, as quantified in B (percent of smooth muscle-actin area covered by amyloid). Sm-actin, smooth muscle actin to mark blood vessels. C. Microhemorrhage in DSL at old age, as seen by Prussian blue staining. No blue sport detected on cortical area of any age of wild type or SL mice, nor in DSL young and middle age mice; but DSL old age mice (>17 month) frequently have microhemorrhage spots with diameters ranger from 10 ~ 50 μm. Average number of spots = 1.35 ± 0.46 per section, N = 10 sections/mouse from 5 animals. **P < 0.01. Scale bars: 50 μm in A, 400 μm in C, and 50 μm in C inset.