Frontal striatal systems and dopamine in normal and pathological behavior

我们的实验室结合神经生理学、药理学和功能成像来研究额叶纹状体系统在行为中的作用。我们的一些实验是由对患者群体的研究激发的，这些研究表明患者在特定任务上存在缺陷。然后，我们在实验室中研究这些任务，以描绘行为背后的神经回路，以及这些神经回路内的大脑区域如何相互作用来驱动行为。最近的工作集中在理解在决策任务中驱动新选项选择的机制。我们使用让参与者选择特定选项并学习每个选项的奖励属性的任务。然后，我们以随机间隔引入新的选择选项。我们发现，通过阻断多巴胺的再吸收，增加多巴胺水平可以增加对新选择的偏好。我们还发现，杏仁核与眶额皮质和腹侧纹状体一起，在对新事物的偏好方面发挥着作用。在实验室的相关实验中，我们一直在研究行动选择，在不同的规则下必须选择行动。我们发现外侧前额皮质和背侧纹状体在这个过程中都起作用。此外，当行动是基于即时可用的信息进行选择时，侧前额皮质似乎比背纹状体更早选择行动。然而，当必须根据过去的结果来选择行动时，背纹状体似乎起着更重要的作用。因此，这两个相互联系的大脑结构似乎在选择行为中发挥互补作用。

Our lab uses a combination of neurophysiology, pharmacology and functional imaging to examine the role of frontal striatal systems in behavior. Several of our experiments are motivated by studies in patient groups that show that patients have deficits on particular tasks. We then study those tasks in the lab to delineate the neural circuits that underlie the behaviors, as well as how brain areas within those neural circuits interact to drive the behavior. Recent work has focused on understanding the mechanisms that drive the choice of novel options in decision making tasks. We use tasks in which participants select particular options and learn the reward properties of each of those options. We then introduce novel choice options at stochastic intervals. We have found that increasing dopamine levels, by blocking dopamine reuptake, can increase preference for novel options. We have also found that the amygdala plays a role in preference for novel objects, in combination with orbital frontal cortex and the ventral striatum. In related experiments in the lab we have been studying action selection, when actions must be selected under different rules. We have found that both lateral prefrontal cortex and the dorsal striatum play a role in this process. Further, lateral prefrontal cortex appears to select actions before the dorsal striatum, when actions are selected on the basis of immediately available information. When actions have to be selected on the basis of past outcomes, however, the dorsal striatum appears to play a more important role. Thus, these two interconnected brain structures appear to play complimentary roles in selecting actions.