Fig. 3

A: Aβ41 is deposited in leptomeningeal blood vessels. Frozen sections from an AD brain were subjected to the immunostaining using antibodies against Aβ41 (green in a − d), Aβ42 (red in b), and Aβ40 (red in d). Double immunostaining against both Aβ41 and Aβ42 demonstrated that the anti-Aβ41 antibody labeled the arterioles (#) in the subarachnoid space, but not the senile plaques (*) in the parenchyma (a and b). Double staining against Aβ41 and Aβ40 is shown. Three different stages of amyloid angiopathies, with weak or no Aβ41 deposition (arrowhead), modest Aβ41 deposition (thin arrow), and with severe Aβ41 deposition (thick arrow) are shown (c and d). Aβ41 was found in the amyloid angiopathy with severe Aβ40 deposition. Contrary to the Aβ40, which deposited in the periphery of adventitia, Aβ41 seemed to be localized in the smooth muscles layer of blood vessels. Scale bars = 50 μm. B: Time course of in vitro Aβ aggregation. Each synthetic Aβ incubated and measured thioflavin T fluorescence. Aβ1–42 aggregates immediately compared to the other variants. Aβ1–40 and Aβ1–41 were similar and showed little aggregation characteristic for 24 h. C: IHC for Aβs accumulation in the occipital cortex sections. Aβ38 and Aβ41 deposited in the leptomeningeal blood vessels in aged SP free brain (NO.9) (a, c). Aβs38, 40, and 41 also deposited in AD (NO.4) and CAA brains (NO.3), but Aβ40 had little deposits in the cortex, including arterioles (e − g, i − k). Amount of Aβ42 deposited in subpial granular cell layers and cortex (h, l). Scale bars = 100 μm (a − d) and 500 μm (e − l)