Affiliated Mental Health Center & Hangzhou Seventh People's Hospital, Interdisciplinary Institute of Neuroscience and Technology, Zhejiang University School of Medicine, Hangzhou, 310013, China.
Key Laboratory of Biomedical Engineering of Ministry of Education, Qiushi Academy for Advanced Studies, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou 310027, China.
Cereb Cortex. 2022 May 14;32(10):2129-2139. doi: 10.1093/cercor/bhab343.
Medial prefrontal cortex (MPFC) and other regions like the occipital cortex (OC) exhibit abnormal neural activity in major depressive disorder (MDD). Their relationship to specific biochemical, psychophysical, and psychopathological changes remains unclear, though. For that purpose, we focus on a particular subregion in OC, namely middle temporal (MT) visual area that is known to mediate the perception of visual motion. Using high-field 7 T magnetic resonance imaging (MRI), including resting state functional MRI and proton magnetic resonance spectroscopy, the amplitude of low-frequency fluctuations (ALFF) of the blood oxygen level-dependent signal in MT, MT-seeded functional connectivity (FC), and gamma-aminobutyric acid (GABA) in MT were investigated. Applying the vision motion psychophysical task, the motion suppression index of subjects was also examined. We demonstrate significantly elevated neural variability (as measured by ALFF) in MT together with decreases in both MT GABA and motion suppression in our MDD sample. Unlike in healthy subjects, MT neural variability no longer modulates the relationship of MT GABA and motion suppression in MDD. MT also exhibits reduction in global inter-regional FC to MPFC in MDD. Finally, elevated MT ALFF relates to specifically retardation in behavior as measured by the Hamilton subscore. Together, MT provides a strong candidate for biomarker in MDD.
内侧前额叶皮层（MPFC）和其他区域，如枕叶皮层（OC），在重度抑郁症（MDD）中表现出异常的神经活动。然而，它们与特定的生化、心理物理和心理病理变化的关系尚不清楚。为此，我们专注于 OC 中的一个特定亚区，即中颞（MT）视觉区，该区域已知介导视觉运动的感知。使用高磁场 7T 磁共振成像（MRI），包括静息状态功能 MRI 和质子磁共振波谱，研究了 MT 中血氧水平依赖信号的低频波动（ALFF）的幅度、MT 种子的功能连接（FC）和 MT 中的γ-氨基丁酸（GABA）。应用视觉运动心理物理任务，还检查了受试者的运动抑制指数。我们在 MDD 样本中证明了 MT 中神经可变性（由 ALFF 测量）显著升高，同时 MT GABA 和运动抑制都降低。与健康受试者不同，MT 神经可变性不再调节 MDD 中 MT GABA 和运动抑制之间的关系。MDD 中还观察到 MT 与 MPFC 之间的全局区域间 FC 减少。最后，MT 中的升高的 ALFF 与 Hamilton 亚评分测量的行为迟缓特别相关。总的来说，MT 是 MDD 中生物标志物的有力候选者。
