Fig. 3

Aβ immunofluorescence combined with Thioflavin S staining. Low-magnification images of Aβx-40, Aβx-42, or Aβ4-x combined with Thioflavin (a–c) show the distribution of Aβ peptides tested and their overlap with the fibrillar amyloid components from Case 1. All peptides are present in amyloid fibrillar conformation in CAA (double white arrows) and in cored plaques (white arrows). Double immunofluorescence with Aβx-40/Aβ4-x and Aβx-42/Aβ4-x was carried out to illustrate the overlap of peptides starting at position 4 with those ending at position either 40 or 42 within the different pathological lesions from Case 1 (d–e). High power magnification images show the distribution of the Aβ peptides carrying the Aβx-40, Aβx-42, and Aβ4-x epitopes in CAA and cored plaques (f–w). Aβx-40 staining was observed in deposits with fibrillar amyloid conformations within the blood vessel, but also in Thioflavin-negative perivascular lesions (f–h, Case 2). Aβx-40 was also abundant in the cored plaques, both in the halo of the core and radiating around the core (i–k, Case 2) but seldomly in the central core itself. Aβx-42 was found deposited in CAA, in patchy deposits around the vessels, and in cored plaques (l–q, Case 2). Aβ4-x was present in the CAA and throughout the cored plaques, including the central core (r–w, Case 1). Scale bar, 50 µm in (a–e) and 20 µm in (f–w)