MEDIAL PREFRONTAL CORTEX RESPONSES TO DOMINANCE-RELATED OLFACTORY CUES IN MICE

Social hierarchy is an important factor shaping behavior in mice. An individual’s position within the social hierarchy influences its ability to acquire resources necessary for survival, such as food, territory, and mating partners. Previous studies have shown that mice can recognize the dominance status of conspecifics based on olfactory information contained in urine. However, how this information is processed in the brain remains unknown.
Here, we show that male mice voluntarily increase their breathing rate (sniffing) when presented with olfactory cues from familiar male conspecifics. Importantly, the magnitude of this sniffing response correlates with the dominance status of the odor donors. During odor presentation, we recorded neuronal activity in the medial prefrontal cortex (mPFC) using Neuropixels 2.0 probes. We found that a large fraction of mPFC neurons respond to social odors and show preferential responses to odors from dominant males. Notably, trial-by-trial variability in neuronal activity is strongly associated with sniffing behavior, which itself is correlated with social rank.
Together, these results indicate that the mPFC - previously implicated in social hierarchy formation and dominant behaviors - also represents information related to the social rank of other individuals. Moreover, mPFC activity is linked to behavioral responses evoked by social odor presentation. Our findings provide insight into how the mPFC may integrate social olfactory information with motor output.