Negative emotional contagion—witnessing others in distress—affects an individual’s emotional responsivity. However, whether it shapes coping strategies when facing future threats remains unknown. We found that mice that briefly observe a conspecific being harmed become resilient, withstanding behavioral despair after an adverse experience. Photometric recordings during negative emotional contagion revealed increased serotonin (5-HT) release in the lateral habenula. Whereas 5-HT and emotional contagion reduced habenular burst firing, limiting 5-HT synthesis prevented burst plasticity. Enhancing raphe-to-habenula 5-HT was sufficient to recapitulate resilience. In contrast, reducing 5-HT release in the habenula made witnessing a conspecific in distress ineffective to promote the resilient phenotype after adversity. These findings reveal that 5-HT supports vicarious emotions and leads to resilience by tuning definite patterns of habenular neuronal activity.

中文翻译：

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情绪传染期间缰核释放的血清素可增强恢复力


负面情绪的传染——目睹他人陷入困境——会影响个人的情绪反应能力。然而，它是否会影响未来威胁时的应对策略仍不得而知。我们发现，短暂观察同种动物受到伤害的小鼠会变得有弹性，在经历不良经历后能够承受行为绝望。负面情绪传染期间的光度记录显示，外侧缰核的血清素（5-HT）释放增加。虽然 5-HT 和情绪传染减少了缰核爆发放电，但限制 5-HT 合成却阻止了爆发可塑性。增强中缝到缰核 5-HT 足以重现恢复力。相比之下，减少缰核中 5-HT 的释放使得目睹同种人陷入困境无法有效促进逆境后的恢复表型。这些发现表明，5-HT 通过调节缰核神经元活动的明确模式来支持替代情绪并带来恢复力。