Department of Psychology, University of Michigan, Ann Arbor, MI, USA.
Center for Biobehavioral Health at the Research Institute of Nationwide Children's Hospital, Columbus, OH, USA.
Neuroimage. 2019 May 1;191:278-291. doi: 10.1016/j.neuroimage.2019.02.009. Epub 2019 Feb 18.
The amygdala is critically involved in processing emotion. Through bidirectional connections, the prefrontal cortex (PFC) is hypothesized to influence amygdala reactivity. However, research that elucidates the nature of amygdala-PFC interactions - through mapping amygdala-prefrontal tracts, quantifying variability among tracts, and linking this variability to amygdala activation - is lacking. Using probabilistic tractography to map amygdala-prefrontal white matter connectivity in 142 adolescents, the present study found that white matter connectivity was greater between the amygdala and the subgenual cingulate, orbitofrontal (OFC), and dorsomedial (dmPFC) prefrontal regions than with the dorsal cingulate and dorsolateral regions. Then, using a machine-learning regression, we found that greater amygdala-PFC white matter connectivity was related to attenuated amygdala reactivity. This effect was driven by amygdala white matter connectivity with the dmPFC and OFC, supporting implicit emotion processing theories which highlight the critical role of these regions in amygdala regulation. This study is among the first to map and compare specific amygdala-prefrontal white matter tracts and to relate variability in connectivity to amygdala activation, particularly among a large sample of adolescents from a well-sampled study. By examining the association between specific amygdala-PFC tracts and amygdala activation, the present study provides novel insight into the nature of this emotion-based circuit.
杏仁核在处理情绪方面起着至关重要的作用。通过双向连接，前额叶皮层（PFC）被假设会影响杏仁核的反应性。然而，缺乏阐明杏仁核-前额叶相互作用本质的研究，这些研究包括映射杏仁核-前额叶束、量化束间的可变性，并将这种可变性与杏仁核激活联系起来。本研究使用概率追踪技术在 142 名青少年中绘制了杏仁核-前额叶白质连接图，发现杏仁核与扣带回下区、眶额（OFC）和背内侧前额叶（dmPFC）区域之间的白质连接比与背侧扣带回和背外侧区域之间的连接更强。然后，使用机器学习回归，我们发现杏仁核-前额叶白质连接越强，杏仁核反应性越低。这种效应是由杏仁核与 dmPFC 和 OFC 的白质连接驱动的，支持了强调这些区域在杏仁核调节中关键作用的隐性情绪处理理论。这项研究是少数几个映射和比较特定杏仁核-前额叶白质束，并将连接的可变性与杏仁核激活联系起来的研究之一，特别是在一个来自样本充足研究的大量青少年样本中。通过检查特定杏仁核-前额叶束与杏仁核激活之间的关联，本研究为理解这种基于情绪的回路的本质提供了新的见解。
