Department of Advanced Neuroimaging, Integrative Brain Imaging Center, National Center of Neurology and Psychiatry, Kodaira, Tokyo 187-8551, Japan.
Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892.
eNeuro. 2017 Dec 8;4(6). doi: 10.1523/ENEURO.0200-17.2017. eCollection 2017 Nov-Dec.
Distinct regions of the frontal cortex connect with their basal ganglia and thalamic counterparts, constituting largely segregated basal ganglia-thalamo-cortical (BTC) circuits. However, any common role of the BTC circuits in different behavioral domains remains unclear. Indeed, whether dysfunctional motor and cognitive BTC circuits are responsible for motor slowing and cognitive slowing, respectively, in Parkinson's disease (PD) is a matter of debate. Here, we used an effortful behavioral paradigm in which the effects of task rate on accuracy were tested in movement, imagery, and calculation tasks in humans. Using nonlinear fitting, we separated baseline accuracy ( ) and "agility" (ability to function quickly) components of performance in healthy participants and then confirmed reduced agility and preserved for the three tasks in PD. Using functional magnetic resonance imaging (fMRI) and diffusion tractography, we explored the neural substrates underlying speeded performance of the three tasks in healthy participants, suggesting the involvement of distinct BTC circuits in cognitive and motor agility. Language and motor BTC circuits were specifically active during speeded performance of the calculation and movement tasks, respectively, whereas premotor BTC circuits revealed activity for speeded performance of all tasks. Finally, PD showed reduced task rate-correlated activity in the language BTC circuits for speeded calculation, in the premotor BTC circuit for speeded imagery, and in the motor BTC circuits for speeded movement, as compared with controls. The present study casts light on the anatomo-functional organization of the BTC circuits and their parallel roles in invigorating movement and cognition through a function of dopamine.
额叶皮层的不同区域与基底神经节和丘脑相对应的区域相连，构成了很大程度上分离的基底神经节-丘脑-皮层（BTC）回路。然而，BTC 回路在不同行为领域的共同作用仍不清楚。事实上，运动和认知 BTC 回路功能障碍是否分别导致帕金森病（PD）中的运动迟缓和认知迟缓，这是一个有争议的问题。在这里，我们使用了一种费力的行为范式，在该范式中，我们在人类的运动、想象和计算任务中测试了任务速率对准确性的影响。使用非线性拟合，我们在健康参与者中分离了基线准确性（）和表现的“敏捷性”（快速发挥功能的能力）成分，然后在 PD 中确认了这三个任务的敏捷性降低和保留。使用功能磁共振成像（fMRI）和弥散张量成像，我们探索了健康参与者完成三个任务的速度表现的神经基础，这表明不同的 BTC 回路参与了认知和运动敏捷性。语言和运动 BTC 回路在计算和运动任务的速度表现中分别表现出特异性激活，而运动前 BTC 回路则揭示了所有任务的速度表现的活动。最后，与对照组相比，PD 在计算速度的语言 BTC 回路中表现出任务速率相关活动减少，在想象速度的运动前 BTC 回路中表现出任务速率相关活动减少，在运动速度的运动 BTC 回路中表现出任务速率相关活动减少。本研究揭示了 BTC 回路的解剖功能组织及其通过多巴胺的功能激发运动和认知的并行作用。
