Innate vocal sounds such as laughing, screaming or crying convey one’s feelings to others. In many species, including humans, scaling the amplitude and duration of vocalizations is essential for effective social communication^1,2,3. In mice, female scent triggers male mice to emit innate courtship ultrasonic vocalizations (USVs)^4,5. However, whether mice flexibly scale their vocalizations and how neural circuits are structured to generate flexibility remain largely unknown. Here we identify mouse neurons from the lateral preoptic area (LPOA) that express oestrogen receptor 1 (LPOA^ESR1 neurons) and, when activated, elicit the complete repertoire of USV syllables emitted during natural courtship. Neural anatomy and functional data reveal a two-step, di-synaptic circuit motif in which primary long-range inhibitory LPOA^ESR1 neurons relieve a clamp of local periaqueductal grey (PAG) inhibition, enabling excitatory PAG USV-gating neurons to trigger vocalizations. We find that social context shapes a wide range of USV amplitudes and bout durations. This variability is absent when PAG neurons are stimulated directly; PAG-evoked vocalizations are time-locked to neural activity and stereotypically loud. By contrast, increasing the activity of LPOA^ESR1 neurons scales the amplitude of vocalizations, and delaying the recovery of the inhibition clamp prolongs USV bouts. Thus, the LPOA disinhibition motif contributes to flexible loudness and the duration and persistence of bouts, which are key aspects of effective vocal social communication.

与生俱来的声音，如笑声、尖叫声或哭声，会将自己的感受传达给他人。在包括人类在内的许多物种中，缩放发声的幅度和持续时间对于有效的社会交流^1,2,3至关重要。在老鼠身上，雌性气味会触发雄性老鼠发出天生的求爱超声波 (USV) ^4,5。然而，老鼠是否灵活地调整它们的发声，以及神经回路是如何构建以产生灵活性的，在很大程度上仍然是未知的。在这里，我们从外侧视前区 (LPOA) 中识别出表达雌激素受体 1 (LPOA ^{ESR1 ) 的小鼠神经元}神经元），并且当被激活时，会引发在自然求爱过程中发出的完整的 USV 音节曲目。神经解剖学和功能数据揭示了一个两步、双突触回路基序，其中初级长程抑制性 LPOA ^ESR1神经元缓解了局部导水管周围灰质 (PAG) 抑制，使兴奋性 PAG USV 门控神经元能够触发发声。我们发现社会背景塑造了广泛的 USV 振幅和回合持续时间。当直接刺激 PAG 神经元时，这种可变性不存在。PAG 诱发的发声与神经活动时间锁定，并且通常响亮。相比之下，增加 LPOA ^{ESR1的活性}神经元缩放发声的幅度，延迟抑制钳的恢复会延长 USV 发作。因此，LPOA 去抑制基序有助于灵活的响度以及发作的持续时间和持久性，这是有效的声音社交交流的关键方面。