BackgroundAlthough the thalamus is known to modulate basal ganglia function related to motor control activity, the abnormal changes within the thalamus during distinct medical complications have been scarcely investigated. In order to explore the feasibility of assessing iron accumulation in the thalamus as an informative biomarker for Parkinson’s disease (PD), this study was designed to employ quantitative susceptibility mapping using a 7 T magnetic resonance imaging system in cynomolgus monkeys. A 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-injected cynomolgus monkey and a healthy control (HC) were examined by 7 T magnetic resonance imaging. Positron emission tomography with 18F-N-(3-fluoro propyl)-2ß-carboxymethoxy-3ß-(4-iodophenyl) nortropane was also employed to identify the relationship between iron deposits and dopamine depletion. All acquired values were averaged within the volume of interest of the nigrostriatal pathway.FindingsCompared with the HC, the overall elevation of iron deposition within the thalamus in the Parkinson’s disease model (about 53.81% increase) was similar to that in the substantia nigra (54.81%) region. Substantial susceptibility changes were observed in the intralaminar part of the thalamus (about 70.78% increase). Additionally, we observed that in the Parkinson’s disease model, binding potential values obtained from positron emission tomography were considerably decreased in the thalamus (97.51%) and substantia nigra (92.48%).ConclusionsThe increased iron deposition in the thalamus showed negative correlation with dopaminergic activity in PD, supporting the idea that iron accumulation affects glutaminergic inputs and dopaminergic neurons. This investigation indicates that the remarkable susceptibility changes in the thalamus could be an initial major diagnostic biomarker for Parkinson’s disease-related motor symptoms.

中文翻译：

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丘脑内磁化率变化的观察：使用 7 T MRI 的健康食蟹猴与帕金森病患者的比较研究

背景虽然已知丘脑调节与运动控制活动相关的基底神经节功能，但很少研究在不同的医学并发症期间丘脑内的异常变化。为了探索评估丘脑中铁积累作为帕金森病 (PD) 信息性生物标志物的可行性，本研究旨在使用 7 T 磁共振成像系统在食蟹猴中采用定量磁敏度绘图。1-甲基-4-苯基-1,2,3,6-四氢吡啶注射的食蟹猴和健康对照 (HC) 通过 7 T 磁共振成像进行检查。还使用 18F-N-（3-氟丙基）-2ß-羧基甲氧基-3ß-（4-碘苯基）去甲托烷的正电子发射断层扫描来确定铁沉积物与多巴胺消耗之间的关系。所有获得的值均在黑质纹状体通路的感兴趣体积内进行平均。 结果与 HC 相比，帕金森病模型中丘脑内铁沉积的总体升高（约 53.81% 增加）与黑质中的相似（54.81 ％） 地区。在丘脑的椎板内部分观察到显着的敏感性变化（增加约 70.78%）。此外，我们观察到在帕金森病模型中，正电子发射断层扫描获得的结合电位值在丘脑 (97.51%) 和黑质 (92.48%) 中显着降低。结论丘脑中铁沉积的增加与多巴胺能活性呈负相关在 PD 中，支持铁积累影响谷氨酰胺能输入和多巴胺能神经元的观点。