Corticosteroid Induced Decoupling of the Amygdala in Men
Corticosteroid Induced Decoupling of the Amygdala in Men
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DOI：
10.1093/cercor/bhr313
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发表时间：
2012-10-01
期刊：
影响因子：
3.7
通讯作者：
Fernandez, Guillen
中科院分区：
文献类型：
--
作者：
Henckens, Marloes J. A. G.;van Wingen, Guido A.;Fernandez, Guillen
杏仁核是警觉的关键调节器，并提高对威胁的注意力。它的活性在受到威胁时被增强，并通过下丘脑-垂体-肾上腺(HPA)轴促进神经内分泌应激反应。众所周知，皮质类固醇通过向大脑提供负面反馈来控制大脑活动和HPA活动。然而，皮质类固醇如何影响连接到杏仁核的神经回路尚不清楚。采用随机、双盲、安慰剂对照设计，我们使用静息状态功能磁共振成像研究了10毫克氢化可的松对男性杏仁核中枢功能连接模式的影响。结果表明，皮质类固醇通常会降低杏仁核的功能连接性。氢化可的松减少了杏仁核与参与启动和维持应激反应的大脑区域--蓝斑、下丘脑和海马体--的“正”功能耦合。此外，氢化可的松减少了杏仁核与额叶中回和颞回的“负”功能耦合，这是已知参与执行控制的大脑区域。一项对照分析没有显示皮质类固醇对视觉皮质耦合的显著调制，表明杏仁核的去耦合并不反映网络连接的普遍减少。这些结果表明，在男性应激后，皮质类固醇可能会减少杏仁核对大脑处理的影响。
The amygdala is a key regulator of vigilance and heightens attention toward threat. Its activity is boosted upon threat exposure and contributes to a neuroendocrine stress response via the hypothalamic-pituitary-adrenal (HPA) axis. Corticosteroids are known to control brain activity as well as HPA activity by providing negative feedback to the brain. However, it is unknown how corticosteroids affect the neural circuitry connected to the amygdala. Implementing a randomized, double-blind, placebo-controlled design, we here investigated the effects of 10-mg hydrocortisone on amygdala-centered functional connectivity patterns in men using resting state functional magnetic resonance imaging. Results showed generally decreased functional connectivity of the amygdala by corticosteroids. Hydrocortisone reduced "positive" functional coupling of the amygdala to brain regions involved in the initiation and maintenance of the stress response; the locus coeruleus, hypothalamus, and hippocampus. Furthermore, hydrocortisone reduced "negative" functional coupling of the amygdala to the middle frontal and temporal gyrus; brain regions known to be involved in executive control. A control analysis did not show significant corticosteroid modulation of visual cortex coupling, indicating that the amygdala decoupling was not reflecting a general reduction of network connectivity. These results suggest that corticosteroids may reduce amygdala's impact on brain processing in the aftermath of stress in men.