PSEN1 and Mental deterioration: These mice harbour FAD-causing mutations in human APP and PSEN1 genes, progressively develop Aβ plaques from as early as 3 months of age and show age-dependent neuroinflammation, synaptic abnormalities, neuronal loss and cognitive decline.35 Six-month-old 5xFAD mice exhibited prominent Aβ labelling marking intraneuronal APP and Aβ that was absent in the hippocampus of WT mice (Fig. 4A and B).