Dynamic mesolimbic dopamine signaling during action sequence learning and expectation violation.
Dynamic mesolimbic dopamine signaling during action sequence learning and expectation violation.
复制标题
动态中唇多巴胺信号在动作序列学习和预期违规过程中。
DOI：
10.1038/srep20231
复制
发表时间：
2016-02-12
影响因子：
4.6
通讯作者：
Wassum KM
中科院分区：
文献类型：
--
作者：
Collins AL;Greenfield VY;Bye JK;Linker KE;Wang AS;Wassum KM
在空间导航过程中，已经检测到了长时间的中脑边缘多巴胺浓度变化，但对产生这种信号传导的条件或它如何随着学习而发展知之甚少。为了解决这一问题，我们监测多巴胺浓度的变化，在整个收购和性能的工具动作序列任务的大鼠脑桥核的核心。随着大鼠执行每个动作序列，检测到多巴胺浓度的长期变化，并在获得奖励后下降。随着学习的进行，多巴胺浓度在序列执行的早期开始上升，并最终从刻板的序列动作中反向传播，只是在最远和最意想不到的奖励预测中短暂升高。在训练有素的大鼠中，如果它们在任务中变得不参与，并且对价值的意外变化做出反应，则与动作序列相关的多巴胺信号被重新激活，但不是所获得奖励的身份。在整个训练和测试过程中，多巴胺信号与序列表现相关。这些结果表明，动作序列可以产生一个长期的模式多巴胺信号在核延髓的核心，这样的信号涉及到的动机基本序列执行的元素，是动态的学习，过度训练和违反奖励预期。
Prolonged mesolimbic dopamine concentration changes have been detected during spatial navigation, but little is known about the conditions that engender this signaling profile or how it develops with learning. To address this, we monitored dopamine concentration changes in the nucleus accumbens core of rats throughout acquisition and performance of an instrumental action sequence task. Prolonged dopamine concentration changes were detected that ramped up as rats executed each action sequence and declined after earned reward collection. With learning, dopamine concentration began to rise increasingly earlier in the execution of the sequence and ultimately backpropagated away from stereotyped sequence actions, becoming only transiently elevated by the most distal and unexpected reward predictor. Action sequence-related dopamine signaling was reactivated in well-trained rats if they became disengaged in the task and in response to an unexpected change in the value, but not identity of the earned reward. Throughout training and test, dopamine signaling correlated with sequence performance. These results suggest that action sequences can engender a prolonged mode of dopamine signaling in the nucleus accumbens core and that such signaling relates to elements of the motivation underlying sequence execution and is dynamic with learning, overtraining and violations in reward expectation.