Anand Amit, Li Yu, Wang Yang, Wu Jingwei, Gao Sujuan, Bukhari Lubna, Mathews Vincent P, Kalnin Andrew, Lowe Mark J
Department of Psychiatry, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA.
Biol Psychiatry. 2005 May 15;57(10):1079-88. doi: 10.1016/j.biopsych.2005.02.021.
Functional imaging studies indicate that imbalances in cortico-limbic activity and connectivity may underlie the pathophysiology of MDD. In this study, using functional Magnetic Resonance Imaging (fMRI), we investigated differences in cortico-limbic activity and connectivity between depressed patients and healthy controls.
Fifteen unmedicated unipolar depressed patients and 15 matched healthy subjects underwent fMRI during which they first completed a conventional block-design activation experiment in which they were exposed to negative and neutral pictures. Next, low frequency blood oxygenation dependent (BOLD) related fluctuations (LFBF) data were acquired at rest and during steady-state exposure to neutral, positive and negative pictures. LFBF correlations were calculated between anterior cingulate cortex (ACC) and limbic regions--amygdala (AMYG), pallidostriatum (PST) and medial thalamus (MTHAL) and used as a measure of cortico-limbic connectivity.
Depressed patients had increased activation of cortical and limbic regions. At rest and during exposure to neutral, positive, and negative pictures cortico-limbic LFBF correlations were decreased in depressed patients compared to healthy subjects.
The finding of increased activation of limbic regions and decreased LFBF correlations between ACC and limbic regions is consistent with the hypothesis that decreased cortical regulation of limbic activation in response to negative stimuli may be present in depression.
功能成像研究表明，皮质-边缘系统活动和连接的失衡可能是重度抑郁症病理生理学的基础。在本研究中，我们使用功能磁共振成像（fMRI）来调查抑郁症患者与健康对照者在皮质-边缘系统活动和连接方面的差异。
15名未接受药物治疗的单相抑郁症患者和15名匹配的健康受试者接受了fMRI检查，在此期间，他们首先完成了一项传统的组块设计激活实验，在实验中他们观看了负面和中性图片。接下来，在静息状态以及在稳态下观看中性、正面和负面图片期间采集低频血氧依赖（BOLD）相关波动（LFBF）数据。计算前扣带回皮质（ACC）与边缘区域——杏仁核（AMYG）、苍白球纹状体（PST）和内侧丘脑（MTHAL）之间的LFBF相关性，并将其用作皮质-边缘系统连接性的指标。
抑郁症患者的皮质和边缘区域激活增加。与健康受试者相比，抑郁症患者在静息状态以及观看中性、正面和负面图片期间，皮质-边缘系统LFBF相关性降低。
边缘区域激活增加以及ACC与边缘区域之间LFBF相关性降低的发现与以下假设一致，即抑郁症患者可能存在对负面刺激的边缘系统激活的皮质调节能力下降。
