Long-lasting internal arousal states motivate and pattern ongoing behaviour, enabling the temporary emergence of innate behavioural programs that serve the needs of an animal, such as fighting, feeding, and mating. However, how internal states shape sensory processing or behaviour remains unclear. In Drosophila, male flies perform a lengthy and elaborate courtship ritual that is triggered by the activation of sexually dimorphic P1 neurons^1,2,3,4,5, during which they faithfully follow and sing to a female^6,7. Here, by recording from males as they court a virtual ‘female’, we gain insight into how the salience of visual cues is transformed by a male’s internal arousal state to give rise to persistent courtship pursuit. The gain of LC10a visual projection neurons is selectively increased during courtship, enhancing their sensitivity to moving targets. A concise network model indicates that visual signalling through the LC10a circuit, once amplified by P1-mediated arousal, almost fully specifies a male’s tracking of a female. Furthermore, P1 neuron activity correlates with ongoing fluctuations in the intensity of a male’s pursuit to continuously tune the gain of the LC10a pathway. Together, these results reveal how a male’s internal state can dynamically modulate the propagation of visual signals through a high-fidelity visuomotor circuit to guide his moment-to-moment performance of courtship.

持久的内部唤醒状态会激发和塑造持续的行为，从而使先天行为程序能够暂时出现，以满足动物的需求，例如战斗、喂养和交配。然而，内部状态如何塑造感觉处理或行为仍不清楚。在果蝇中，雄性果蝇会进行漫长而复杂的求爱仪式，这是由性二态性 P1 神经元^1,2,3,4,5的激活触发的，在此期间它们忠实地跟随雌性^6,7. 在这里，通过记录男性在向虚拟“女性”求爱时的记录，我们深入了解视觉线索的显着性如何被男性的内部唤醒状态转变为持续的求爱追求。LC10a 视觉投射神经元的增益在求偶过程中选择性增加，增强了它们对移动目标的敏感性。一个简洁的网络模型表明，通过 LC10a 电路的视觉信号一旦被 P1 介导的唤醒放大，几乎完全指定了男性对女性的跟踪。此外，P1 神经元活动与男性追求不断调整 LC10a 通路增益的强度的持续波动相关。一起，