Quantification of the hippocampal amyloid burden in experimental and control groups also showed that animals injected with Aβ−containing cattle brain homogenate doubled the regular amount of Aβ (0.11 ± 0.02 vs. 0.05 ± 0.01%) found in the hippocampus of APP/PS1 at this age (Figure 3C). This evidence concerns the gene PSEN1 and amyloidosis.