APP and Alzheimer disease: As the reduction of endogenous estrogen in aged Ar+/− female mice (12 months) was sufficient enough to promote early development of Alzheimer’s disease pathology in APP mice as we previously published (Yue et al., 2005), the less response to the estrogen deficiency-related depressive-like behavior in FST in Ar+/− mice might be related to the mice at younger age (3 months) and shorter duration of estrogen deficiency (Estrada-Camarena et al., 2011).