重度抑郁症的大脑网络

重度抑郁症(MDD)的病理生理机制尚不清楚,因为它影响了广泛的动机、情感和认知过程,这些过程很难解开。因此,患者和健康对照组之间的任务表现差异可能与动机水平的不同有关,而不是信息处理本身。在“休息”或无任务状态下应用神经成像技术可以避免与表现相关的混淆,并且是测量基线大脑活动的有力方法(Gusnard和Raichle, 2001)。所谓的静息状态网络(RSN)的发现(Biswal et al., 1995),即即使在没有任务的情况下也表现出高度相互联系的大脑区域集,被认为是健康和患病大脑功能研究中的一个里程碑。

重度抑郁症的大脑网络

图1所示。对比fMRI (A)和EEG (B)数据,患者>对照组,DMN>TPN。

大多数rsn在与外部导向注意相关的任务中活动增加,被称为任务积极网络(TPNs),而一个网络在大多数此类任务中活动减少,分别被称为任务消极网络(Fox et al., 2005)。后一种网络通常被称为默认模式网络(DMN),它与自我参照过程有关(Buckner et al. 2008;Raichle, 2015)。因为抑郁症与外部导向注意力的恶化和自我关注的增强有关(Grimm等人,2009;Watkins和Teasdale, 2004),因此毫不奇怪,重度抑郁症患者表现出DMN内的连通性增加而tpn内的连通性降低(Hamilton等人,2011,2013;Marchetti et al., 2012)。在MDD患者中,DMN相对于TPN的“优势”在皮层定位尚不完全清楚。此外,这种效应已经使用功能磁共振成像进行了研究,其与神经元事件的关系仍然存在争议(例如,Debener等人,2006)。基于电生理数据对这些现象的确认将大大增加我们对其神经起源的信心,并有可能使用更便宜的设备进行研究。在这项研究中,我们使用基于种子的连通性分析,对MDD患者和健康对照的静息状态fMRI和EEG数据进行了测试。 EEG data were analyzed using a combination of beamformer spatial filtering with seed-based connectivity estimation (Brookes et al., 2011; De Pasquale et al., 2010; Hipp et al., 2012). In MDD patients, as compared to controls, left insula, pallidum/putamen, amygdala, and left dorso- and ventrolateral prefrontal cortex were more strongly connected with DMN than with TPN seeds (Fig. 1). In EEG, all significant effects were obtained in the delta frequency band, in line with the hypothesis linking these oscillations with motivational processes and pathological conditions (Knyazev, 2012). Thus, both fMRI and EEG data show that in MDD patients, major emotion and attention regulation circuits are more strongly connected with DMN than with TPN implying they are more prepared to respond to internally generated self-related thoughts than to environmental challenges. Both fMRI and EEG data point to the left prefrontal cortex broadly defined as the site, which in depressed individuals is stronger connected with the DMN than with the TPN. It is well known that left prefrontal cortex damage leads to hedonic deficits and increases depressive symptoms (Davidson, 2001). It could be speculated that these left-sided brain areas are normally under the control of TPN and are easily activated by environmental stimuli, but in depressed individuals preoccupied with self-focused rumination they fall under control of the DMN and are not able anymore to respond adequately to environmental cues.

根纳季·克尼亚泽夫,亚历山大·萨沃斯季诺夫,安德烈·波恰罗夫,伊万·布拉克,
叶夫根尼·a·奥西波夫,艾琳娜·a·菲利莫诺娃,亚历山大·e·萨里格金,柳波米尔·i·阿夫塔纳斯

俄罗斯新西伯利亚生理与基础医学研究所

出版

重性抑郁症的任务正网络和任务负网络:功能磁共振成像和脑电图的联合研究。
Knyazev GG, Savostyanov AN, Bocharov AV, Brak IV, Osipov EA, Filimonova EA, Saprigyn AE, Aftanas LI
[J]情感失调。2018年8月1日

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