Dissociable dopamine dynamics for learning and motivation
Dissociable dopamine dynamics for learning and motivation
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DOI：
10.1038/s41586-019-1235-y
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发表时间：
2019-06-06
期刊：
影响因子：
64.8
通讯作者：
Berke, Joshua D.
中科院分区：
文献类型：
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作者：
Mohebi, Ali;Pettibone, Jeffrey R.;Berke, Joshua D.
腹侧被盖区（VTA）向丘脑腹侧核（NAc）的多巴胺投射对奖励工作动机和奖励驱动学习至关重要。多巴胺如何支持这两种功能尚不清楚。多巴胺细胞尖峰可以编码预测错误，这是适应行为计算理论中重要的学习信号。相比之下，多巴胺的释放随着动物接近奖励而增加，反映了奖励期望。这种不匹配可能反映了行为任务的差异，多巴胺细胞尖峰或多巴胺释放的尖峰独立调制的缓慢变化。在这里，我们比较了尖峰确定腹侧被盖区多巴胺细胞与NAc多巴胺释放在同一决策任务。提示即将到来的奖励增加了扣球和释放。然而，NAc核心多巴胺释放也与动态变化的奖励预期，没有相应的变化，腹侧被盖区多巴胺细胞尖峰。我们的研究结果表明，多巴胺的释放是如何调节，以实现不同的功能的根本区别：广播突发信号促进学习，而本地控制驱动的动机。
The dopamine projection from ventral tegmental area (VTA) to nucleus accumbens (NAc) is critical for motivation to work for rewards and reward-driven learning. How dopamine supports both functions is unclear. Dopamine cell spiking can encode prediction errors, which are vital learning signals in computational theories of adaptive behaviour. By contrast, dopamine release ramps up as animals approach rewards, mirroring reward expectation. This mismatch might reflect differences in behavioural tasks, slower changes in dopamine cell spiking or spike-independent modulation of dopamine release. Here we compare spiking of identified VTA dopamine cells with NAc dopamine release in the same decision-making task. Cues that indicate an upcoming reward increased both spiking and release. However, NAc core dopamine release also covaried with dynamically evolving reward expectations, without corresponding changes in VTA dopamine cell spiking. Our results suggest a fundamental difference in how dopamine release is regulated to achieve distinct functions: broadcast burst signals promote learning, whereas local control drives motivation.