Impaired conflict resolution associated with anhedonia in socially defeated mice
Approach-avoidance conflict, social defeat, defensive behaviors, ethoexperimental analysis, anhedonia, sucrose-preference, psychiatric disorders.
Emotional conflict has long been recognized as a core symptom of many social stress related psychiatric disorders. However, animal models designed to study impaired social interactions in such disorders are still undeveloped to assess conflict behaviors. Here, we investigated chronically defeated mice for specific defensive behavioral patterns associated with emotional conflict during social interaction rechallenge. Our results show that social defeat stress exacerbates avoidance tendencies during approach-avoidance conflict toward unknown conspecifics. Avoidance tendencies were specifically represented by increased flight occurrences close after social investigation events, which characterize an organized defensive pattern of risk assessment behavior followed by full expression of fear (flight behaviors). Moreover, mice with low preference for a palatable sucrose solution (anhedonic) display long lasting expression of defensive behaviors and social avoidance. Our study highlights the importance of species-typical behaviors to better understand stress related pathology associated with emotional conflict and different levels of hedonic state.