Specific Hypothalamic Neurons Required for Perceiving Conspecific Male Cues Relevant to Inter-Male Aggression

Abstract

The hypothalamus critically regulates innate social interactions, but how hypothalamic neurons transducing sex-related sensory signals emitted by conspecifics to trigger appropriate behaviors remains largely unknown. We addressed this issue by identifying specific hypothalamic neurons involved in perceiving conspecific male cues relevant to inter-male aggression. By in vivo recording of neuronal activities in behaving mice, we showed that neurons expressing dopamine transporter (DAT+) in the ventral premammillary nucleus (PMv) of the hypothalamus responded specifically to male urine cues in a vomeronasal organ (VNO)-dependent manner in naive males. Retrograde trans-synaptic tracing further revealed a specific group of neurons in the bed nucleus of the stria terminalis (BNST) that convey male-relevant signals from VNO to PMv. Moreover, ablation of PMvDAT+ neurons blocked the preference for male urine cues and reduced inter-male attacks. Thus, PMvDAT+ neurons exemplify the function of specific hypothalamic neurons responsible for transforming sex-related sensory signals into perception and behaviors.