Fig. 6

Progressive accumulation of microvascular amyloid leads to increased numbers of activated caspase-3 positive cells in rTg-DI rats. a–f Representative images from 3-month-old wild-type (a–c) and rTg-DI (d–f) rats and 12-month wild-type (g–i) and rTg-DI (j–l) rats. Brain sections were stained with DAPI (blue), immunolabeled with a rabbit polyclonal antibody to active caspase 3 to identify apoptotic cells (red) and with mouse monoclonal antibody 66.1 to identify cerebral microvascular amyloid (green). Scale bars = 50 μm. g Quantitation of activated caspase 3 positive cells in wild-type rats (black bars) and rTg-DI rats (gray bars) in the cortex, hippocampus, and thalamus. Data shown are mean ± SD of n = 5 rats per group. **P < 0.01, ***P < 0.001. In wild-type rats, very few activated caspase 3-positive cells were observed, but in rTg-DI rat brains, markedly elevated numbers of activated caspase 3-positive cells were seen surrounding microvascular amyloid in all brain regions