Ensemble activity in rat corticostriatal circuits during habit learning

描述(申请人提供)：当我们重复以目标为导向的行为时，这些行为通常会变得习惯性和例行公事，以至于我们几乎可以不假思索地执行它们。这种养成习惯的能力在我们的日常生活中是非常宝贵的。当我们能够以习惯性模式运作时，我们就释放了认知资源。目标导向的行为成为习惯的过程引起了基础科学家和医生的极大兴趣，因为当这个习惯过程出错时，行为问题可能会出现。在以重复行为为主要症状的神经精神障碍中，习惯形成可能处于过度驱动状态。当我们失去养成习惯的能力时，思想和行动可能会失去正常日常生活赋予我们行为的基本组织的一部分。这项拟议工作的目标是确定从深思熟虑的行为表现到习惯性行为表现的这种转变背后的电路级神经机制，在这种模式中，行为继续执行，而不参考最初的目标。众所周知，前额叶皮质和纹状体的一部分对于习惯的形成是必要的，但它们如何使行为转变为习惯行为仍不清楚。在习惯形成的整个过程中，我们同时记录了前额叶皮质和纹状体的神经活动，从早期习得到习惯根深蒂固的过度训练期。我们发现，随着从目标导向行为向习惯性行为的转变，纹状体不同部位和前额叶皮质神经元的放电模式都发生了显著的变化。我们现在提议进行实验，以确定这些区域是如何相互作用的，以及当老鼠养成习惯时，是否通过扰乱或沉默个别区域来确定是否存在控制区域，以了解这个大脑区域网络如何导致灵活的目标导向行为和较不灵活的习惯行为之间的转变。从帕金森氏症到强迫症再到精神病，行为的灵活性和固定性之间的平衡失调在许多神经学和神经精神障碍中是至关重要的。因此，所提出的实验与NIMH了解、预防和治疗精神疾病的使命直接相关。

DESCRIPTION (provided by applicant): As we repeat goal-directed behaviors, these behaviors often become habitual and so routine that we can perform them almost without thinking. This capacity to form habits is very valuable in our normal lives. When we can operate in a habitual mode, we free up cognitive resources. The process by which goal-directed behaviors become habitual has attracted great interest among basic scientists and also among physicians, because when this habit-process goes awry, behavioral problems can emerge. In neuropsychiatric disorders in which repetitive behaviors are predominant symptoms, habit forming may be in overdrive. When we lose the ready facility to form habits, thoughts and actions may lose part of the fundamental organization that normal routines confer on our behavior. The goal of the proposed work is to identify the circuit-level neural mechanisms that underlie this transition from deliberative behavioral performance to a habitual mode of performance in which the behavior continues to be performed without reference to the original goal. It is known that parts of prefrontal cortex and the striatum are necessary for habit formation, but how they act to allow the behavioral shift to habitual behavior still are not understood. We have recorded neural activity in the prefrontal cortex and striatum simultaneously through the entire process of habit formation from early acquisition to the over-training period when the habit becomes ingrained. We have found that as the shift from goal-directed to habitual behavior occurs, there are remarkable changes in the firing patterns of neurons both in different parts of the striatum and in the prefrontal cortex. We now propose experiments to determine how these regions interact and whether there are 'controller' regions by perturbing or silencing individual zones as rats form habits, in order to understand how this network of brain regions bring about shifts between flexible goal-directed behavior and less flexible habitual behavior. Disturbances in the balance between flexibility and fixity of behavior are critical in a number of neurologic and neuropsychiatric disorders ranging from Parkinson's disease to obsessive-compulsive disorder to psychosis. Thus, the experiments proposed are directly related to the mission of the NIMH to understand, prevent and cure mental illness.