In exploring the impact of systemic inflammation on microglial morphology and function, Tejera et al. (2019) [26] utilized Cx3cr1-eGFP and APP/PS1 mouse models with in vivo two-photon laser scanning microscopy (2PLSM) to reveal age-dependent microglial changes in Alzheimer’s disease (AD). Here, PSEN1 is linked to early-onset autosomal dominant Alzheimer disease.