Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, USA.
Department of Neuroscience, Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA.
Nature. 2023 Nov;623(7986):375-380. doi: 10.1038/s41586-023-06580-w. Epub 2023 Sep 27.
Hunger, thirst, loneliness and ambition determine the reward value of food, water, social interaction and performance outcome. Dopamine neurons respond to rewards meeting these diverse needs, but it remains unclear how behaviour and dopamine signals change as priorities change with new opportunities in the environment. One possibility is that dopamine signals for distinct drives are routed to distinct dopamine pathways. Another possibility is that dopamine signals in a given pathway are dynamically tuned to rewards set by the current priority. Here we used electrophysiology and fibre photometry to test how dopamine signals associated with quenching thirst, singing a good song and courting a mate change as male zebra finches (Taeniopygia guttata) were provided with opportunities to retrieve water, evaluate song performance or court a female. When alone, water reward signals were observed in two mesostriatal pathways but singing-related performance error signals were routed to Area X, a striatal nucleus specialized for singing. When courting a female, water seeking was reduced and dopamine responses to both water and song performance outcomes diminished. Instead, dopamine signals in Area X were driven by female calls timed with the courtship song. Thus the dopamine system handled coexisting drives by routing vocal performance and social feedback signals to a striatal area for communication and by flexibly re-tuning to rewards set by the prioritized drive.
饥饿、口渴、孤独和野心决定了食物、水、社交互动和表现结果的奖励价值。多巴胺神经元对满足这些不同需求的奖励做出反应,但目前尚不清楚随着环境中出现新的机会,行为和多巴胺信号如何随着优先级的变化而变化。一种可能性是,不同驱动力的多巴胺信号被路由到不同的多巴胺通路。另一种可能性是,给定通路上的多巴胺信号会根据当前优先级的奖励进行动态调整。在这里,我们使用电生理学和光纤光度法来测试雄性斑胸草雀(Taeniopygia guttata)在获得获取水、评估歌曲表现或求偶的机会时,与解渴、唱好歌和求偶相关的多巴胺信号如何变化。当单独时,在两条中脑纹状体通路上观察到水奖励信号,但与歌唱相关的表现错误信号被路由到专门用于歌唱的纹状体核区 X。当求偶时,对水的寻求减少,对水和歌曲表现结果的多巴胺反应也减少。相反,X 区的多巴胺信号是由与求偶歌曲同步的雌性叫声驱动的。因此,多巴胺系统通过将声音表现和社交反馈信号路由到用于交流的纹状体区域,并通过灵活地重新调整优先级驱动的奖励来处理共存的驱动力。