Vanderbilt University, Nashville, TN.
Vanderbilt University Medical Center, Nashville, TN.
J Cogn Neurosci. 2023 Nov 1;35(11):1806-1822. doi: 10.1162/jocn_a_02048.
Limbic and motor integration is enabled by a mesial temporal to motor cortex network. Parkinson disease (PD) is characterized by a loss of dorsal striatal dopamine but relative preservation of mesolimbic dopamine early in disease, along with changes to motor action control. Here, we studied 47 patients with PD using the Simon conflict task and [18F]fallypride PET imaging. Additionally, a cohort of 16 patients participated in a single-blinded dextroamphetamine (dAMPH) study. Task performance was evaluated using the diffusion model for conflict tasks, which allows for an assessment of interpretable action control processes. First, a voxel-wise examination disclosed a negative relationship, such that longer non-decision time is associated with reduced D2-like binding potential (BPND) in the bilateral putamen, left globus pallidus, and right insula. Second, an ROI analysis revealed a positive relationship, such that shorter non-decision time is associated with reduced D2-like BPND in the amygdala and ventromedial OFC. The difference in non-decision time between off-dAMPH and on-dAMPH trials was positively associated with D2-like BPND in the globus pallidus. These findings support the idea that dysfunction of the traditional striatal-motor loop underlies action control deficits but also suggest that a compensatory parallel limbic-motor loop regulates motor output.
边缘和运动的整合是由内侧颞叶到运动皮层网络实现的。帕金森病（PD）的特征是背侧纹状体多巴胺的丧失，但在疾病早期相对保留中脑边缘多巴胺，同时运动动作控制也发生变化。在这里，我们使用 Simon 冲突任务和 [18F] fallypride PET 成像研究了 47 名 PD 患者。此外，16 名患者参加了一项单盲右旋苯丙胺（dAMPH）研究。使用冲突任务的扩散模型评估任务表现，该模型允许评估可解释的动作控制过程。首先，体素-wise 检查显示出负相关关系，即较长的非决策时间与双侧壳核、左侧苍白球和右侧脑岛的 D2 样结合潜能（BPND）降低有关。其次，ROI 分析显示出正相关关系，即较短的非决策时间与杏仁核和腹内侧 OFC 的 D2 样 BPND 降低有关。off-dAMPH 和 on-dAMPH 试验之间的非决策时间差异与苍白球中的 D2 样 BPND 呈正相关。这些发现支持这样一种观点，即传统的纹状体-运动回路的功能障碍是动作控制缺陷的基础，但也表明代偿性的平行边缘-运动回路调节运动输出。
