Sinha Rajita, Lacadie Cheryl M, Constable R Todd, Seo Dongju
Yale Stress Center, Yale University School of Medicine, New Haven, CT 06519; Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511; Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06520; Child Study Center, Yale University School of Medicine, New Haven, CT 06519;
Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT 06520.
Proc Natl Acad Sci U S A. 2016 Aug 2;113(31):8837-42. doi: 10.1073/pnas.1600965113. Epub 2016 Jul 18.
Active coping underlies a healthy stress response, but neural processes supporting such resilient coping are not well-known. Using a brief, sustained exposure paradigm contrasting highly stressful, threatening, and violent stimuli versus nonaversive neutral visual stimuli in a functional magnetic resonance imaging (fMRI) study, we show significant subjective, physiologic, and endocrine increases and temporally related dynamically distinct patterns of neural activation in brain circuits underlying the stress response. First, stress-specific sustained increases in the amygdala, striatum, hypothalamus, midbrain, right insula, and right dorsolateral prefrontal cortex (DLPFC) regions supported the stress processing and reactivity circuit. Second, dynamic neural activation during stress versus neutral runs, showing early increases followed by later reduced activation in the ventrolateral prefrontal cortex (VLPFC), dorsal anterior cingulate cortex (dACC), left DLPFC, hippocampus, and left insula, suggested a stress adaptation response network. Finally, dynamic stress-specific mobilization of the ventromedial prefrontal cortex (VmPFC), marked by initial hypoactivity followed by increased VmPFC activation, pointed to the VmPFC as a key locus of the emotional and behavioral control network. Consistent with this finding, greater neural flexibility signals in the VmPFC during stress correlated with active coping ratings whereas lower dynamic activity in the VmPFC also predicted a higher level of maladaptive coping behaviors in real life, including binge alcohol intake, emotional eating, and frequency of arguments and fights. These findings demonstrate acute functional neuroplasticity during stress, with distinct and separable brain networks that underlie critical components of the stress response, and a specific role for VmPFC neuroflexibility in stress-resilient coping.
积极应对是健康应激反应的基础,但支持这种适应性应对的神经过程尚不为人所知。在一项功能磁共振成像(fMRI)研究中,我们采用了一种简短、持续暴露的范式,将高度应激、威胁性和暴力性刺激与无厌恶的中性视觉刺激进行对比,结果显示,在应激反应的脑回路中,主观、生理和内分泌方面均有显著增加,且神经激活呈现出与时间相关的动态不同模式。首先,杏仁核、纹状体、下丘脑、中脑、右侧脑岛和右侧背外侧前额叶皮层(DLPFC)区域应激特异性的持续增加支持了应激处理和反应回路。其次,应激与中性状态下的动态神经激活表明,腹外侧前额叶皮层(VLPFC)、背侧前扣带回皮层(dACC)、左侧DLPFC、海马体和左侧脑岛早期激活增加,随后激活减少,提示存在应激适应反应网络。最后,可以观察到腹内侧前额叶皮层(VmPFC)的动态应激特异性动员,其特征是最初活动不足,随后VmPFC激活增加,这表明VmPFC是情绪和行为控制网络的关键位点。与此发现一致,应激期间VmPFC中更大的神经灵活性信号与积极应对评分相关,而VmPFC中较低的动态活动也预示着现实生活中更高水平的适应不良应对行为,包括大量饮酒、情绪化进食以及争吵和打架的频率。这些发现表明,应激期间存在急性功能性神经可塑性,具有不同且可分离的脑网络,这些网络构成了应激反应关键组成部分的基础,并且VmPFC神经灵活性在应激适应性应对中具有特定作用。