The brain dopamine (DA) system participates in forming and expressing memory. Despite a well-established role of DA neurons in the ventral tegmental area in memory formation, the exact DA circuits that control memory expression remain unclear. Here, we show that DA neurons in the dorsal raphe nucleus (DRN) and their medulla input control the expression of incentive memory. DRN DA neurons are activated by both rewarding and aversive stimuli in a learning-dependent manner and exhibit elevated activity during memory recall. Disrupting their physiological activity or DA synthesis blocks the expression of natural appetitive and aversive memories as well as drug memories associated with opioids. Moreover, a glutamatergic pathway from the lateral parabrachial nucleus to the DRN selectively regulates the expression of reward memories associated with opioids or foods. Our study reveals a specialized DA subsystem important for memory expression and suggests new targets for interventions against opioid addiction.

中文翻译：

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Raphe多巴胺系统控制激励性记忆的表达。

脑多巴胺（DA）系统参与记忆的形成和表达。尽管DA神经元在腹侧被盖区的记忆形成中已确立作用，但控制记忆表达的确切DA电路仍不清楚。在这里，我们显示背缝核（DRN）中的DA神经元及其髓质输入控制了激励记忆的表达。DRN DA神经元通过学习依赖的方式被奖励和厌恶刺激所激活，并在记忆回忆期间表现出增强的活动。破坏其生理活性或DA合成会阻止自然食性和厌恶性记忆以及与阿片类药物相关的药物记忆的表达。此外，从臂外侧臂旁核到DRN的谷氨酸能途径选择性调节与阿片样物质或食物相关的奖励记忆的表达。我们的研究揭示了一个专门的DA子系统，对于记忆表达很重要，并提出了针对阿片类药物成瘾的新靶标。