Overriding Phasic Dopamine Signals Redirects Action Selection during Risk/Reward Decision Making
Overriding Phasic Dopamine Signals Redirects Action Selection during Risk/Reward Decision Making
复制标题
DOI：
10.1016/j.neuron.2014.08.033
复制
发表时间：
2014-10-01
期刊：
影响因子：
16.2
通讯作者：
Floresco, Stan B.
中科院分区：
文献类型：
--
作者：
Stopper, Colin M.;Tse, Maric T. L.;Floresco, Stan B.
多巴胺（DA）传输的阶段性增加和减少编码奖励预测错误，被认为有助于奖励相关的学习，但这些信号如何在需要评估不同奖励的更复杂的情况下指导动作选择仍不清楚。我们操纵相位DA信号，而大鼠进行风险/奖励决策任务，使用时间离散刺激外侧缰核（LHb）或头内侧被盖核（RMTg）抑制DA爆发（证实与神经生理学研究）或腹侧被盖区（VTA）覆盖相位下降。当大鼠在小/确定和大/风险奖励之间选择时，LHb或RMTg刺激，时间锁定到这些奖励之一的传递，重定向偏向于替代选项，而VTA刺激后，nonrewarded选择增加了风险的选择。在选择之前进行LHb刺激会使偏好远离更偏好的选项。因此，相位DA信号提供关于最近的动作是否被奖励的反馈，以更新决策策略并将动作导向更期望的奖励。
Phasic increases and decreases in dopamine (DA) transmission encode reward prediction errors thought to facilitate reward-related learning, yet how these signals guide action selection in more complex situations requiring evaluation of different reward remains unclear. We manipulated phasic DA signals while rats performed a risk/reward decision-making task, using temporally discrete stimulation of either the lateral habenula (LHb) or rostromedial tegmental nucleus (RMTg) to suppress DA bursts (confirmed with neurophysiological studies) or the ventral tegmental area (VTA) to override phasic dips. When rats chose between small/certain and larger/risky rewards, LHb or RMTg stimulation, time-locked to delivery of one of these rewards, redirected bias toward the alternative option, whereas VTA stimulation after nonrewarded choices increased risky choice. LHb stimulation prior to choices shifted bias away from more preferred options. Thus, phasic DA signals provide feedback on whether recent actions were rewarded to update decision policies and direct actions toward more desirable reward.