biostudies-literaturePaquelet GENIMH NIH HHS2664-2679.e8https://www.ebi.ac.uk/biostudies/studies/S-EPMC9575686biostudies-literatureUnknown110(16)The serotonin system modulates a wide variety of emotional behaviors and states, including reward processing, anxiety, and social interaction. To reveal the underlying patterns of neural activity, we visualized serotonergic neurons in the dorsal raphe nucleus (DRN^5-HT) of mice using miniaturized microscopy during diverse emotional behaviors. We discovered ensembles of cells with highly correlated activity and found that DRN^5-HT neurons are preferentially recruited by emotionally salient stimuli as opposed to neutral stimuli. Individual DRN^5-HT neurons responded to diverse combinations of salient stimuli, with some preference for valence and sensory modality. Anatomically defined subpopulations projecting to either a reward-related structure (the ventral tegmental area) or an anxiety-related structure (the bed nucleus of the stria terminalis) contained all response types but were enriched in reward- and anxiety-responsive cells, respectively. Our results suggest that the DRN serotonin system responds to emotional salience using ensembles with mixed selectivity and biases in downstream connectivity.NeuronSingle-cell activity and network properties of dorsal raphe nucleus serotonin neurons during emotionally salient behaviors.PMC9575686R01 MH068542K08 MH116368T32 MH015144Carrion KLacefield COZhou PHen RMiller BRPaquelet GEfalseSingle-cell activity and network properties of dorsal raphe nucleus serotonin neurons during emotionally salient behaviors.The serotonin system modulates a wide variety of emotional behaviors and states, including reward processing, anxiety, and social interaction. To reveal the underlying patterns of neural activity, we visualized serotonergic neurons in the dorsal raphe nucleus (DRN^5-HT) of mice using miniaturized microscopy during diverse emotional behaviors. We discovered ensembles of cells with highly correlated activity and found that DRN^5-HT neurons are preferentially recruited by emotionally salient stimuli as opposed to neutral stimuli. Individual DRN^5-HT neurons responded to diverse combinations of salient stimuli, with some preference for valence and sensory modality. Anatomically defined subpopulations projecting to either a reward-related structure (the ventral tegmental area) or an anxiety-related structure (the bed nucleus of the stria terminalis) contained all response types but were enriched in reward- and anxiety-responsive cells, respectively. Our results suggest that the DRN serotonin system responds to emotional salience using ensembles with mixed selectivity and biases in downstream connectivity.2022-01-01T00:00:00Z2022 Aug2026-05-28T02:02:04.813Z2025-04-04T03:00:11.927ZS-EPMC95756863570073710.1016/j.neuron.2022.05.015