纹状体多巴胺信号反映小鼠感知到的线索-行动-结果关联
2024.02.18德国慕尼黑工业大学Simon N. Jacob课题组发现，纹状体多巴胺信号反映小鼠感知到的线索-行动-结果关联。相关论文于2024年1月30日在线发表于国际学术期刊《自然—神经科学》。
研究人员对雄性小鼠的纹状体进行了光纤光度多巴胺测量，当时它们正在根据隐含的和不断变化的任务规则学习线索-行动-结果关联。行为和多巴胺数据的强化学习模型表明，规则的改变会导致所学线索-行动-结果关联的调整。规则改变后，小鼠会摒弃已学过的关联，并重新设定结果预期。线索和结果触发的多巴胺信号变得不耦合，并依赖于所采用的行为策略。随着小鼠学会新的联想，线索和结果触发的多巴胺信号与任务表现之间的耦合重新出现。
这些研究结果表明，多巴胺能奖赏预测错误反映了行为主体感知到的控制位置。
据介绍，纹状体多巴胺通过充当教学信号驱动联想学习。许多工作都集中在简单的学习范式上，包括巴甫洛夫学习和工具学习。然而，高级认知要求动物对其环境产生内部概念，将感官刺激、行动和结果灵活地联系起来。
附：英文原文
Title: Striatal dopamine signals reflect perceived cue–action–outcome associations in mice
Author: Bernklau, Tobias W., Righetti, Beatrice, Mehrke, Leonie S., Jacob, Simon N.
Issue&Volume: 2024-01-30
Abstract: Striatal dopamine drives associative learning by acting as a teaching signal. Much work has focused on simple learning paradigms, including Pavlovian and instrumental learning. However, higher cognition requires that animals generate internal concepts of their environment, where sensory stimuli, actions and outcomes become flexibly associated. Here, we performed fiber photometry dopamine measurements across the striatum of male mice as they learned cue–action–outcome associations based on implicit and changing task rules. Reinforcement learning models of the behavioral and dopamine data showed that rule changes lead to adjustments of learned cue–action–outcome associations. After rule changes, mice discarded learned associations and reset outcome expectations. Cue- and outcome-triggered dopamine signals became uncoupled and dependent on the adopted behavioral strategy. As mice learned the new association, coupling between cue- and outcome-triggered dopamine signals and task performance re-emerged. Our results suggest that dopaminergic reward prediction errors reflect an agent’s perceived locus of control.
DOI: 10.1038/s41593-023-01567-2
Source: https://www.nature.com/articles/s41593-023-01567-2
期刊信息
Nature Neuroscience：《自然—神经科学》，创刊于1998年。隶属于施普林格·自然出版集团，IF：28.771
