Matsumoto Hideyuki, Tian Ju, Uchida Naoshige, Watabe-Uchida Mitsuko
Center for Brain Science, Harvard University, Cambridge, United States.
Department of Molecular and Cellular Biology, Harvard University, Cambridge, United States.
Elife. 2016 Oct 19;5:e17328. doi: 10.7554/eLife.17328.
Dopamine is thought to regulate learning from appetitive and aversive events. Here we examined how optogenetically-identified dopamine neurons in the lateral ventral tegmental area of mice respond to aversive events in different conditions. In low reward contexts, most dopamine neurons were exclusively inhibited by aversive events, and expectation reduced dopamine neurons' responses to reward and punishment. When a single odor predicted both reward and punishment, dopamine neurons' responses to that odor reflected the integrated value of both outcomes. Thus, in low reward contexts, dopamine neurons signal value prediction errors (VPEs) integrating information about both reward and aversion in a common currency. In contrast, in high reward contexts, dopamine neurons acquired a short-latency excitation to aversive events that masked their VPE signaling. Our results demonstrate the importance of considering the contexts to examine the representation in dopamine neurons and uncover different modes of dopamine signaling, each of which may be adaptive for different environments.
多巴胺被认为可调节从愉悦和厌恶事件中学习的过程。在此，我们研究了小鼠腹侧被盖区外侧经光遗传学鉴定的多巴胺能神经元在不同条件下对厌恶事件的反应。在低奖赏情境中，大多数多巴胺能神经元仅被厌恶事件抑制，且预期会降低多巴胺能神经元对奖赏和惩罚的反应。当单一气味同时预示奖赏和惩罚时，多巴胺能神经元对该气味的反应反映了两种结果的综合价值。因此，在低奖赏情境中，多巴胺能神经元以一种通用货币整合有关奖赏和厌恶的信息，发出价值预测误差（VPE）信号。相比之下，在高奖赏情境中，多巴胺能神经元对厌恶事件获得了短潜伏期兴奋，掩盖了它们的VPE信号。我们的结果证明了考虑情境以检查多巴胺能神经元表征的重要性，并揭示了多巴胺信号传导的不同模式，其中每种模式可能对不同环境具有适应性。
