Exploring cortico-striatal connectivity across different domains of cognition combining TMS and fMRI

大脑的额叶部分和深层核团共同参与了运动的控制以及做出决定等心理过程。这些结构经常在不同的神经和精神疾病中受到影响，包括帕金森氏症和精神分裂症。我们的实验室已经开发了一些任务，利用功能磁共振成像(MRI)等技术来梳理这些区域中单个结构的作用。特别是，我们能够将参与执行过程的额叶和尾状核(大脑的深层结构)的两个子区域的功能分开。我们还开发了一些任务，以区分额叶更后部区域和壳核(另一种深层大脑结构)在动作执行中的功能。 然而，到目前为止，我们还不能研究这些不同的区域在执行心理和运动任务时是如何相互作用的。在这项提议的背景下，我们将使用一种新技术--经颅磁刺激(TMS)，它允许我们在短时间内刺激或阻碍外脑特定部分的活动，并使用功能磁共振研究其对大脑活动的影响。特别是，我们将研究刺激额叶不同区域对参与者在休息或进行特定心理或运动锻炼时大脑深层结构中观察到的活动模式的影响。 在健康个体的额叶和脑深部结构相互作用的研究中，TMS和功能磁共振的拟议混合在加拿大是独一无二的，对于理解这些不同区域之间的关系和沟通是非常宝贵的。未来，我们将对帕金森氏症患者进行类似的实验，并将我们对过程的知识应用于健康参与者，以更好地了解疾病的神经起源。

Together, the frontal portion and the deep nuclei of the brain are involved in the control of movement as well as mental processes such as making decisions. These structures are often affected in different neurological and psychiatric disorders, including Parkinson's disease and schizophrenia. Our laboratory has developed tasks to tease apart the role of individual structures in these regions, using techniques such as functional magnetic resonance imaging (MRI). In particular, we were able to separate the functions of two sub-regions of the frontal lobe and the caudate nucleus (a deep structure of the brain) that are involved in executive processes. We have also developed tasks to distinguish the function of a more posterior region of the frontal lobe and the putamen, another deep brain structure, in the execution of movements. Until now, however, we have not been able to investigate how these different regions interact with each other during the performance of our mental and motor tasks. In the context of this proposal, we will be using a novel technique, transcranial magnetic stimulation (TMS), which allows us to stimulate or hinder the activity of specific portions of the outer brain during a short period of time, and investigate its effects on brain activity using functional MRI. In particular, we will investigate the effect of the stimulation of various regions of the frontal lobe on the patterns of activity observed in the deep structures of the brain while participants are either at rest, or while performing specific mental or motor exercises. The proposed mixture of TMS and functional MRI in the study of frontal lobe and deep brain structure interactions in healthy individuals is unique in Canada, and is invaluable in understanding the relationships and communication between these different regions. In the future, we will perform similar experiments with patients with Parkinson's disease, and apply our knowledge of processes in healthy participants in order to better understand the neural origins of the disease.