PSEN1 and Alzheimer disease: Also, tuft synapse density in aged APP/PS1 mice showed a non-significant decrease compared to juvenile animals (AD: aged 2.32 ± 0.12 vs. juvenile 2.79 ± 0.15 puncta/μm, Tukey’s multiple-comparisons corrected p = 0.091; Figure S5C), and both groups were significantly lower than weaned APP/PS1 mice (AD: weaned 3.89 ± 0.23 puncta/μm).