Department of Neurology, University Clinic of Lübeck, Lübeck, Germany; Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, Lübeck, Germany.
Department of Neurology, University Clinic of Lübeck, Lübeck, Germany; Department of Psychology, University of Lübeck, Lübeck, Germany; Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands.
Neuropsychologia. 2022 Jan 28;165:108113. doi: 10.1016/j.neuropsychologia.2021.108113. Epub 2021 Dec 9.
Many studies point toward volume reductions in the amygdala as a potential neurostructural marker for trait aggression. However, most of these findings stem from clinical samples, rendering unclear whether the findings generalize to non-clinical populations. Furthermore, the notion of neural networks suggests that interregional correlations in gray matter volume (i.e., structural covariance) can explain individual differences in aggressive behavior beyond local univariate associations. Here, we tested whether structural covariance between amygdala subregions and the rest of the brain is associated with self-reported aggression in a large sample of healthy young students (n = 263; 49% women). Salivary testosterone concentrations were measured for a subset of n = 40 male and n = 36 female subjects, allowing us to investigate the influence of endogenous testosterone on structural covariance. Aggressive individuals showed enhanced covariance between left superficial amygdala (SFA) and left dorsal anterior insula (dAI), but lower covariance between right laterobasal amygdala (LBA) and right dorsolateral prefrontal cortex (dlPFC). These structural patterns overlap with functional networks involved in the genesis and regulation of aggressive behavior, respectively. With increasing endogenous testosterone, we observed stronger structural covariance between right centromedial amygdala (CMA) and right medial prefrontal cortex in men and between left CMA and bilateral orbitofrontal cortex in women. These results speak for structural covariance of amygdala subregions as a robust correlate of trait aggression in healthy individuals. Moreover, regions that showed structural covariance with the amygdala modulated by either testosterone or aggression did not overlap, suggesting a complex role of testosterone in human social behavior beyond facilitating aggressiveness.
许多研究指出杏仁核体积减小可能是特质攻击性的潜在神经结构标志物。然而，这些发现大多来自临床样本，不清楚这些发现是否适用于非临床人群。此外，神经网络的概念表明，灰质体积的区域间相关性（即结构协方差）可以解释攻击性行为的个体差异，而不仅仅是局部的单变量关联。在这里，我们在一个由 263 名健康年轻学生组成的大样本中（49%为女性）测试了杏仁核亚区与大脑其他区域之间的结构协方差是否与自我报告的攻击性有关。对于一小部分 n = 40 名男性和 n = 36 名女性受试者，我们测量了唾液睾酮浓度，允许我们调查内源性睾酮对结构协方差的影响。攻击性个体表现出左浅表层杏仁核（SFA）和左背侧前岛叶（dAI）之间增强的协方差，但右后基杏仁核（LBA）和右背外侧前额叶皮层（dlPFC）之间的协方差较低。这些结构模式分别与涉及攻击性行为产生和调节的功能网络重叠。随着内源性睾酮的增加，我们观察到男性右侧中央杏仁核（CMA）和右侧内侧前额叶皮层之间以及女性左侧 CMA 和双侧眶额皮层之间的结构协方差增强。这些结果表明杏仁核亚区的结构协方差是健康个体特质攻击性的一个稳健相关物。此外，与杏仁核结构协方差受睾酮或攻击性调节的区域并不重叠，这表明睾酮在人类社会行为中的作用复杂，不仅仅是促进攻击性。
