Aβ immunostainings of Sw2 patient’s frontal cortex. a: The plaques in frontal cortex are most numerous and compact in layers 2 and 3. b and c: Higher magnifications of the region within the rectangle. b: Antibody Aβx-40 stains the plaques, including their centres, relatively homogeneously. c: In a consecutive section abAβx-42 leaves the centres pale disclosing the targetoid pattern of many plaques (arrows). In general the plaques are sharply delineated like the so-called cotton wool plaques (cf. Figure 7b and Additional file 1: Figure S9). Note the small diffuse Aβ deposits (arrowhead) and thin subpial patches (open arrow) in layer 1. d: In occipital cortex (striate area) the variable deposition of Aβ in different cortical layers is prominent. Note the abundant vascular Aβ deposition in meningeal and penetrating parenchymal arteries as well as in capillaries deep in layer 4. (See also Additional file 2: Figure S7c). e-h: Sections from the same region as in a-c. e: Mid-domain abAβ17–24 gives the most comprehensive staining of plaques. f-h: The more N-terminal antibodies highlight plaque centres. (bar in a 500 μm for a and d; bar in b 200 μm for b-c and e-h).