The hypothalamus regulates innate social interactions, but how hypothalamic neurons transduce sex-related sensory signals emitted by conspecifics to trigger appropriate behaviors remains unclear. Here, we addressed this issue by identifying specific hypothalamic neurons required for sensing 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 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. Inhibition of PMv^DAT+ neurons abolished the preference for male urine cues and reduced inter-male attacks, while activation of these neurons promoted urine marking and aggression. Thus, PMv^DAT+ neurons exemplify a hypothalamic node that transforms sex-related chemo-signals into recognition and behaviors.

下丘脑调节先天性社交互动，但下丘脑神经元如何转导特定物种发出的性别相关的感觉信号以触发适当的行为尚不清楚。在这里，我们通过识别特定的下丘脑神经元来解决这个问题，这些特定的下丘脑神经元是感应与雄性间侵略有关的特定雄性线索所需的。通过在行为小鼠体内记录神经元活动，我们发现神经元表达多巴胺转运蛋白（DAT ⁺下丘脑腹侧前乳突核（PMv）对雄性幼鼠的犁鼻鼻器官（VNO）依赖性方式对雄性尿指示有反应。逆行的突触追踪进一步揭示了纹状体终末期床床核（BNST）中特定的神经元组，这些神经元将男性相关信号从VNO传递到PMv。抑制PMv ^{DAT +}神经元消除了对男性尿液线索的偏好并减少了男性间的攻击，而这些神经元的激活促进了尿液的标记和侵略性。因此，PMv ^{DAT +}神经元代表了下丘脑结点，该结节将与性别有关的化学信号转化为识别和行为。