Figure 4: Increased cerebral capillary amyloid deposition in bigenic Tg-SwDI/Tg2576 mouse brain.

Transgenic mouse brain sections (from 6 to 18 months old) were stained for fibrillar amyloid using thioflavin S (green) and immunolabelled for cerebral blood vessels using an antibody to collagen IV (red). (a–c) Tg-SwDI mice; (d–f) Tg2576 mice; and (g–i) bigenic Tg-SwDI/Tg2576 mice. Scale bar, 25 μm. Transgenic mouse brain sections (from 18 months old) were stained for fibrillar amyloid using thioflavin S and immunolabelled for cerebral blood vessels using an antibody to collagen IV. (j) The area occupied by parenchymal fibrillar amyloid plaques was determined in specific brain regions of each transgenic mouse line using stereological principles as described in Methods. The data presented are the mean±s.d. of 4–6 mice per group. (k) The frequency of cerebral capillary amyloid was determined in specific brain regions of each transgenic mouse line using stereological principles as described in Methods. The data presented are the mean±s.d. of 4–6 mice per group. (l) Microvessels exhibiting amyloid deposition were selected from distinct brain regions of each transgenic mouse line and the volume of microvascular amyloid was determined as described in Methods. The data presented are the mean±s.d. of a total of 50 microvessels selected from each brain region of three mice per group. Pair-wise comparisons were made using t-test and significant differences (P<0.05) are indicated and limited to three decimal places.