Given that aged APP/PS1 mice exhibit progressive development of Aβ plaques, which begins at 8 months of age (Garcia-Alloza et al., 2006), together with altered synaptic transmission and impaired memory (Mcclean and Holscher, 2014), we next asked whether aging worsened expression of mitochondrial proteins in AD model mice. The gene discussed is PSEN1; the disease is Alzheimer disease.