Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, USA.
Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
Neuroscience. 2021 Jul 1;466:162-172. doi: 10.1016/j.neuroscience.2021.05.012. Epub 2021 May 15.
Neighborhood disadvantage and community violence are common in poor, urban communities and are risk factors for emotional dysfunction. Emotional processes are supported by neural circuitry that includes the prefrontal cortex (PFC), hippocampus, amygdala, and hypothalamus. These brain regions are connected by white matter pathways that include the cingulum bundle, uncinate fasciculus, stria terminalis, and fornix. Emotional function varies with the microstructure of these white matter pathways. However, it is not clear whether the microstructure of these pathways varies with risk factors for emotional dysfunction (e.g., neighborhood disadvantage and violence exposure). Therefore, determining the relationships between neighborhood disadvantage, violence exposure, and white matter microstructure may offer insight into the neural mechanisms by which adverse life experiences alter developing neural systems. The current study investigated the association that exposure to neighborhood disadvantage and violence have with the quantitative anisotropy (QA), a measure of the amount of directional water diffusion, of the cingulum bundle, uncinate fasciculus, stria terminalis, and fornix. Neighborhood disadvantage (M = 11.20) and violence exposure (M = 11.20; M = 13.05; M = 16.20; M = 19.25) were assessed during adolescence and participants returned for magnetic resonance imaging as young adults (N = 303; M = 20.25, SD = 1.55), during which diffusion weighted brain images were collected. The QA of the cingulum bundle, uncinate fasciculus, and stria terminalis/fornix varied negatively with neighborhood disadvantage such that the QA of these white matter tracts decreased as neighborhood disadvantage increased. Violence exposure was not related to QA in any tract (i.e., cingulum bundle, uncinate fasciculus, and stria terminalis/fornix) after correction for multiple comparisons. These results suggest that an adolescent's neighborhood may play an important role in the microstructure (i.e., QA) of white matter pathways that connect brain regions that support emotional function.
社区劣势和社区暴力在贫穷的城市社区中很常见，是情绪功能障碍的风险因素。情绪过程得到包括前额叶皮层（PFC）、海马体、杏仁核和下丘脑在内的神经回路的支持。这些脑区通过包括扣带束、钩束、终纹和穹窿在内的白质通路连接。情绪功能随这些白质通路的微观结构变化而变化。然而，尚不清楚这些通路的微观结构是否会因情绪功能障碍的风险因素（例如社区劣势和暴力暴露）而发生变化。因此，确定社区劣势、暴力暴露与白质微观结构之间的关系可能有助于深入了解不良生活经历改变发育中神经系统的神经机制。本研究调查了暴露于社区劣势和暴力与扣带束、钩束、终纹和穹窿的定量各向异性（QA）之间的关联，QA 是测量水扩散方向的量度。在青春期期间评估了社区劣势（M=11.20）和暴力暴露（M=11.20；M=13.05；M=16.20；M=19.25），参与者在成年早期（N=303；M=20.25，SD=1.55）返回进行磁共振成像，在此期间收集了扩散加权脑图像。扣带束、钩束和终纹/穹窿的 QA 与社区劣势呈负相关，即随着社区劣势的增加，这些白质束的 QA 降低。在进行多次比较校正后，暴力暴露与任何束（即扣带束、钩束和终纹/穹窿）的 QA 均无关。这些结果表明，青少年所处的社区可能在连接支持情绪功能的脑区的白质通路的微观结构（即 QA）中发挥重要作用。
