APP and Alzheimer disease: To gain insight into these questions, we investigated the impact of natural and pathological aging in social odor-evoked sniffing behavior, social-odor habituation/dishabituation, and sociability during the aging process of wild-type C57/BL6 mice and amyloid precursor protein (APP) and presenilin 1 (PS1) double transgenic mice (APP/PS1Het mice, therein), a widely used animal model of AD [24–26].