Interactive effects of <i>OXTR</i> and <i>GAD1</i> on envy-associated behaviors and neural responses

Inequity aversion (negative feelings induced by outcome differences between the self and other) plays a key role in human social behaviors. The neurotransmitters oxytocin and GABA have been implicated in neural responses to inequity. However, it remains poorly understood not only how individual genetic factors related to oxytocin and GABA affect the neural mechanisms behind inequity aversion, but also how these genes interact. To address these issues, we examined relationships between genotypes, behavioral decisions and brain activities during the ultimatum game. We identified interactive effects between the polymorphisms of the oxytocin receptor gene (OXTR) and glutamate decarboxylase 1 gene for GABA synthesis (GAD1) on envy aversion (i.e., disadvantageous inequity aversion) and on envy-induced activity in the dorsal ACC (dACC). Thus, our integrated approach suggested interactive genetic effects between OXTR and GAD1 on envy aversion and the underlying neural substrates.不公平厌恶（即由自身与他人的结果差异引发的负面情绪）在人类社会行为中发挥关键作用。催产素（oxytocin）与γ-氨基丁酸（GABA）这两种神经递质已被证实与个体对不公平厌恶的神经反应相关。然而，目前学界仍未明确两个核心问题：一是与催产素和γ-氨基丁酸相关的个体遗传因素如何影响不公平厌恶背后的神经机制；二是这些基因之间存在怎样的交互作用。为解决上述问题，本研究考察了最后通牒博弈（ultimatum game）过程中基因型、行为决策与脑活动之间的关联。本研究发现，催产素受体基因（OXTR）与负责γ-氨基丁酸合成的谷氨酸脱羧酶1基因（GAD1）的多态性，对嫉妒厌恶（即不利条件下的不公平厌恶）以及背侧前扣带回皮层（dACC）中由嫉妒引发的脑活动存在交互影响。综上，本研究的整合分析方法表明，OXTR与GAD1之间的遗传交互作用会影响个体的嫉妒厌恶行为及其背后的神经基础。