Graham Alice M, Pfeifer Jennifer H, Fisher Philip A, Carpenter Samuel, Fair Damien A
Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, USA.
Department of Psychology, University of Oregon, Portland, OR, USA.
J Child Psychol Psychiatry. 2015 Nov;56(11):1212-22. doi: 10.1111/jcpp.12409. Epub 2015 Mar 23.
Extensive animal research has demonstrated the vulnerability of the brain to early life stress (ELS) with consequences for emotional development and mental health. However, the influence of moderate and common forms of stress on early human brain development is less well-understood and precisely characterized. To date, most work has focused on severe forms of stress, and/or on brain functioning years after stress exposure.
In this report we focused on conflict between parents (interparental conflict), a common and relatively moderate form of ELS that is highly relevant for children's mental health outcomes. We used resting state functional connectivity MRI to examine the coordinated functioning of the infant brain (N = 23; 6-12-months-of-age) in the context of interparental conflict. We focused on the default mode network (DMN) due to its well-characterized developmental trajectory and implications for mental health. We further examined DMN strength as a mediator between conflict and infants' negative emotionality.
Higher interparental conflict since birth was associated with infants showing stronger connectivity between two core DMN regions, the posterior cingulate cortex (PCC) and the anterior medial prefrontal cortex (aMPFC). PCC to amygdala connectivity was also increased. Stronger PCC-aMPFC connectivity mediated between higher conflict and higher negative infant emotionality.
The developing DMN may be an important marker for effects of ELS with relevance for emotional development and subsequent mental health. Increasing understanding of the associations between common forms of family stress and emerging functional brain networks has potential to inform intervention efforts to improve mental health outcomes.
大量动物研究表明，早期生活压力（ELS）会使大脑变得脆弱，进而影响情绪发展和心理健康。然而，对于适度且常见的压力形式对人类早期大脑发育的影响，我们了解较少，也缺乏精确的描述。迄今为止，大多数研究都集中在严重的压力形式，和/或压力暴露数年之后的大脑功能。
在本报告中，我们聚焦于父母之间的冲突（父母间冲突），这是一种常见且相对适度的早期生活压力形式，与儿童的心理健康结果高度相关。我们使用静息态功能连接磁共振成像来研究父母间冲突背景下婴儿大脑（N = 23；6至12个月大）的协同功能。由于其明确的发育轨迹和对心理健康的影响，我们重点关注默认模式网络（DMN）。我们进一步将DMN强度作为冲突与婴儿负面情绪之间的中介进行研究。
自出生以来父母间冲突程度越高，婴儿大脑两个核心DMN区域，即后扣带回皮层（PCC）和前内侧前额叶皮层（aMPFC）之间的连接就越强。PCC与杏仁核之间的连接也有所增加。更强的PCC-aMPFC连接在更高的冲突水平和更高的婴儿负面情绪之间起到了中介作用。
发育中的DMN可能是早期生活压力影响的一个重要标志，与情绪发展及后续心理健康相关。加深对常见家庭压力形式与新兴功能性脑网络之间关联的理解，有可能为改善心理健康结果的干预措施提供依据。
