Dopamine neurons of the ventral tegmental area (VTA) regulate reward association and motivation. It remains unclear whether there are distinct dopamine populations to mediate these functions. Using mouse genetics, we isolated two populations of dopamine-producing VTA neurons with divergent projections to the nucleus accumbens (NAc) core and shell. Inhibition of VTA-core-projecting neurons disrupted Pavlovian reward learning, and activation of these cells promoted the acquisition of an instrumental response. VTA-shell-projecting neurons did not regulate Pavlovian reward learning and could not facilitate acquisition of an instrumental response, but their activation could drive robust responding in a previously learned instrumental task. Both populations are activated simultaneously by cues, actions, and rewards, and this co-activation is required for robust reinforcement of behavior. Thus, there are functionally distinct dopamine populations in the VTA for promoting motivation and reward association, which operate on the same timescale to optimize behavioral reinforcement.

中文翻译：

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不同多巴胺投射人群在行为强化中的协同作用。

腹侧被盖区 (VTA) 的多巴胺神经元调节奖励关联和动机。目前尚不清楚是否有不同的多巴胺群体来介导这些功能。使用小鼠遗传学，我们分离出两个产生多巴胺的 VTA 神经元群，它们对伏隔核 (NAc) 核和壳具有不同的投射。VTA 核心投射神经元的抑制扰乱了巴甫洛夫奖赏学习，而这些细胞的激活促进了器乐反应的获得。VTA 壳投射神经元不调节巴甫洛夫奖赏学习，也不能促进器乐反应的获得，但它们的激活可以驱动先前学习的器乐任务中的强烈响应。两个群体同时被提示、行动和奖励激活，这种共同激活是行为强化所必需的。因此，VTA 中存在功能不同的多巴胺群体，用于促进动机和奖励关联，它们在相同的时间尺度上运作以优化行为强化。