Center for Alcohol and Addiction Studies, Brown University, Box G-S121-4, 121 South Main St., Providence, RI 02912, USA; Department of Behavioral and Social Sciences, School of Public Health, Brown University, Providence, RI, USA; Carney Institute for Brain Science, Brown University, Providence, RI, USA.
Neuroscience Graduate Program, Brown University, Providence, RI, USA.
Neuroimage. 2021 Jan 15;225:117509. doi: 10.1016/j.neuroimage.2020.117509. Epub 2020 Oct 27.
Proton magnetic resonance spectroscopy (H-MRS) is a noninvasive imaging technique that measures the concentration of metabolites in defined areas of the human brain in vivo. The underlying structure of natural metabolism-emotion relationships is unknown. Further, there is a wide range of between-person differences in metabolite concentration in healthy individuals, but the significance of this variation for understanding emotion in healthy humans is unclear. Here we investigated the relationship of two emotional constructs, agency and flexibility, with the metabolites glutamate and glutamine (Glx), N-acetylaspartate (tNAA), choline (Cho), creatine (tCr), and myo-inositol (Ins) in the right dorsal anterior cingulate cortex (dACC) in medically and psychiatrically healthy volunteers (N = 20, 9 female; mean age = 22.8 years, SD = 3.40). The dACC was selected because this region is an integrative hub involved in multiple brain networks of emotion, cognition and behavior. Emotional traits were assessed using the Multidimensional Personality Questionnaire Brief Form (MPQ-BF), an empirically derived self-report instrument with an orthogonal factor structure. Phenotypes evaluated were positive and negative agency (MPQ-BF Social Potency, Aggression), emotional and behavioral flexibility (MPQ-BF Absorption, Control-reversed), and positive and negative affect (MPQ-BF Social Closeness; Stress Reaction, Alienation). The resting concentration of tNAA in the dACC was robustly positively correlated with Absorption (r = +0.56, unadjusted p = .005), moderately positively correlated with Social Potency (r = +0.42, unadjusted p = .03), and robustly negatively correlated with Aggression (r = -0.59, unadjusted p = .003). Absorption and Aggression accounted for substantial variance in tNAA (R = 0.31, 0.35; combined R = 0.50), and survived correction for multiple comparisons (Holm-Bonferroni adjusted p = .032, 0.021, respectively). dACC Glx and Cho had modest relationships with behavioral flexibility and social affiliation that did not survive this multiple correction, providing effect sizes for future work. Principal Component Analysis (PCA) revealed a three-factor orthogonal solution indicating specific relationships between: 1) Glx and behavioral engagement; 2) Cho and affiliative bonding; and 3) tNAA and a novel dimension that we term neuroaffective reserves. Our results inform the neurobiology of agency and flexibility and lay the groundwork for understanding mechanisms of natural emotion using H-MRS.
质子磁共振波谱（H-MRS）是一种非侵入性成像技术，可测量体内人脑特定区域代谢物的浓度。自然代谢-情绪关系的基本结构尚不清楚。此外，健康个体之间代谢物浓度存在广泛的个体差异，但这种变化对理解健康人类的情绪意义尚不清楚。在这里，我们研究了两种情绪结构，即能动性和灵活性，与右背侧前扣带皮层（dACC）中谷氨酸和谷氨酰胺（Glx）、N-乙酰天冬氨酸（tNAA）、胆碱（Cho）、肌酸（tCr）和肌醇（Ins）的代谢物之间的关系在医学和精神上健康的志愿者中（N=20，9 名女性；平均年龄 22.8 岁，标准差 3.40）。选择 dACC 是因为该区域是一个整合枢纽，涉及情绪、认知和行为的多个大脑网络。使用多维人格问卷简表（MPQ-BF）评估情绪特征，这是一种具有正交因子结构的经验衍生的自我报告工具。评估的表型是积极和消极的能动性（MPQ-BF 社会能力，攻击性），情感和行为灵活性（MPQ-BF 吸收，控制反转），以及积极和消极情绪（MPQ-BF 社交亲密感；应激反应，疏远感）。dACC 中 tNAA 的静息浓度与吸收（r=+0.56，未调整 p=0.005）呈强正相关，与社会能力（r=+0.42，未调整 p=0.03）呈中度正相关，与攻击性（r=-0.59，未调整 p=0.003）呈强负相关。吸收和攻击性解释了 tNAA 的大量差异（R=0.31，0.35；合并 R=0.50），并且在多次比较校正后仍然存在（Holm-Bonferroni 校正后的 p 值分别为 0.032 和 0.021）。dACC Glx 和 Cho 与行为灵活性和社会联系有适度的关系，但在这种多重校正后并未存活，为未来的工作提供了效应大小。主成分分析（PCA）显示出一个三因素正交解，表明：1）Glx 与行为参与；2）Cho 与亲和结合；3）tNAA 与我们称为神经情感储备的新维度。我们的结果为能动性和灵活性的神经生物学提供了信息，并为使用 H-MRS 理解自然情绪的机制奠定了基础。
