Chronic unpredictable mild stress alters odor hedonics and adult olfactory neurogenesis in mice

Experiencing chronic stress significantly increases the risk for depression. Depression is a complex disorder with varied symptoms across patients. However, feeling of sadness and decreased motivation, diminished pleasure (anhedonia) appear to be core most depressive pathology. Odorants are potent signals that serve critical role in social interactions, avoiding danger, consummatory behaviors. Diminished quality olfactory function associated negative effects on life leading aggravating Odor hedonic value (I like or I dislike this smell) dominant feature olfaction guides approach avoidance behavior odor source. The neural representation odorants carried by granule cells bulb, which functions modulate cortical relay information. bulb those dentate gyrus two major populations adult brain continued neurogenesis into adulthood. In hippocampus, has been linked development maintenance depression symptoms. Here, we hypothesize mild can alter hedonics through neurogenesis, contributing broader anhedonia phenotype stress-associated To test this, mice were subjected unpredictable then tested measures depressive-like behaviors, hedonics, neurogenesis. Chronic led selective effect diminishing attraction pleasant but not unpleasant odorants, an was accompanied specific decrease percentage adult-born responding bulb.