Psychology Department, University of Colorado Denver, United States.
Psychology Department, University of Colorado Denver, United States.
Brain Res. 2019 Jun 15;1713:32-41. doi: 10.1016/j.brainres.2018.11.043. Epub 2018 Dec 11.
The mesocorticolimbic dopamine pathway is generally considered to be a reward pathway. While shortsighted, there is a strong basis for this view of dopamine function. Here, we first describe the role of phasic dopamine release events in reward seeking. We then explain why these release events are being reconsidered as value signals and how we applied behavioral economics to confirm they play a causal role in the valuation of reward. Just because dopamine release can function as a dopamine reward value signal however, does not imply that dopamine is solely a reward molecule. Rather, mesocorticolimbic dopamine appears to mediate many adaptive behaviors, including: reward seeking, avoidance, escape and fear-associated conditioned freezing. While more studies are needed before a consensus is reached on when, where and how dopamine mediates aversively-motivated behavior, its involvement is almost irrefutable. Thus, we next describe the role dopamine plays in these ethologically-relevant defensive behaviors. We conclude by describing our recent behavioral economics results that reveal a causal role for dopamine in the valuation of avoidance.
中脑边缘多巴胺通路通常被认为是一种奖励通路。虽然这种观点目光短浅,但它有很强的基础。在这里,我们首先描述了相位多巴胺释放事件在奖励寻求中的作用。然后,我们解释了为什么这些释放事件被重新视为价值信号,以及我们如何应用行为经济学来确认它们在奖励估值中起因果作用。然而,仅仅因为多巴胺释放可以作为多巴胺奖励价值信号发挥作用,并不意味着多巴胺仅仅是一种奖励分子。相反,中脑边缘多巴胺似乎介导了许多适应性行为,包括:奖励寻求、回避、逃避和与恐惧相关的条件性冻结。虽然在多巴胺何时、何地以及如何介导厌恶动机行为方面还需要更多的研究才能达成共识,但它的参与几乎是不可否认的。因此,我们接下来描述了多巴胺在这些与行为相关的防御行为中的作用。最后,我们描述了我们最近的行为经济学研究结果,这些结果揭示了多巴胺在回避估值中的因果作用。