Frontal Striatal Systems and Dopamine in Normal and Pathological Behavior

我们的实验室使用神经生理学，药理学和功能成像的组合来研究额叶纹状体系统在行为中的作用。我们的几个实验的动机是对病人群体的研究，表明病人在特定的任务上有缺陷。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，以及这些神经回路中的大脑区域如何相互作用以驱动行为。最近的工作集中在理解决策任务中驱动新选项选择的机制。我们使用的任务中，参与者选择特定的选项，并学习这些选项中的每一个奖励属性。然后，我们介绍了新的选择选项在随机区间。我们发现，通过阻止多巴胺再吸收来增加多巴胺水平，可以增加对新选择的偏好。我们还发现，杏仁核与眶额叶皮层和腹侧纹状体一起，在对新事物的偏好中发挥作用。在实验室的相关实验中，我们一直在研究动作选择，当动作必须在不同的规则下选择时。我们已经发现，外侧前额叶皮层和背侧纹状体在这一过程中发挥作用。此外，外侧前额叶皮质似乎在背侧纹状体之前选择行动，当行动是根据立即可用的信息选择时。然而，当必须根据过去的结果选择行动时，背侧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动方面发挥着互补的作用。

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.