Effects of aging and genotype on circadian rhythms, sleep, and clock gene expression in APPxPS1 knock-in mice, a model for Alzheimer's disease

► Circadian rhythms are altered in Alzheimer's disease (AD) patients. ► Circadian rhythms and clock genes were tested in an AD model, APPxPS1 knock-in mice. ► Clock genes and sleep-wake but not activity rhythms were changed in APPxPS1 mice. ► APPxPS1 and wild-type (CD-1/129) mice exhibited significant daytime activity. ► Age-related decreases in activity and sleep were observed in both genotypes.