COMT基因对注意控制神经基础的调控效应：影像遗传学研究的元分析

为探索注意控制能力个体差异的遗传来源, 当前研究主要关注儿茶酚胺氧位甲基转移酶(catechol-O-Methyltransferase, COMT)基因对参与注意控制加工的前额叶脑区的调控作用。为进一步回答COMT基因是否也对全脑范围的注意脑区具有调控作用, 本文对17篇遗传影像学研究进行元分析。结果发现, COMT基因Val/Val (vv)基因型的被试在注意控制任务下, 不仅前额叶脑区的激活水平高于Met/Met(mm)基因型的被试, 在前扣带回和后扣带回等前额叶之外的脑区激活水平也高于mm基因型的被试, 而且在这些脑区的效应值(vv>mm)都较大(Cohen’s d > 0.8)。由此, 元分析结果表明：COMT基因不仅调控前额叶脑区, 而且对形成注意控制网络的多个脑区都有调控效应。此结果提示注意控制能力的个体差异可能部分的来自于COMT基因对注意控制网络的调控作用。

The Effect of COMT Gene Polymorphism on the Neural Substrate of Attention Control:A Meta-analysis of Imaging Genetics Studies

Investigation on the genetic origin of individual differences in attention control has become increasingly popular.A majority of imaging genetics studies primarily focused on the effect of catechol-O-methyltransferase (COMT) gene on the activation of the prefrontal cortex during attention control tasks.However,neuroimaging studies have consistently demonstrated that the neural substrate of attention control comprises cortical regions not only in the prefrontal cortex but also in the parietal and cingulate cortex,which together form a neural network of attention control.In addition,these regions are also richly innervated with dopaminergic projections.Therefore,it is possible that COMT gene polymorphism modulates the activation of the parietal and cingulated cortices during attention control as well.To examine the effect of COMT gene polymorphism,we used meta-analysis approach to re-analyze results from seventeen imaging genetics studies on the effect of COMT gene polymorphism under attention control tasks.These studies consisted of a total number of 742 participants (208 Met/Met,315 Val/Met,and 219 Val/Val).The coordinates of peak voxels reported in the studies were projected onto a brain template to visualize the distribution of the effect of COMT gene polymorphism.Then,the effect size of COMT gene polymorphism in each region was calculated with Comprehensive Meta-Analysis program (CMA).Finally,a power analysis was performed with G*power program.The meta-analysis indicated that Val/Val homozygotes showed higher activation not only in the prefrontal cortex but also in regions such as anterior cingulate cortex (ACC) and posterior cingulate cortex (PCC) than Met/Met homozygotes.Besides,the effect sizes of COMT gene polymorphism in these regions were above 0.8 (Cohen’s d).In sum,the meta-analysis provides evidence that COMT gene polymorphism modulates activation in multiple cortical regions of the attention control network,suggesting that individual differences in attention control partly originate from the modulation of COMT gene polymorphism on the attention control network,not just the prefrontal cortex.Thus,our study provides clues for future COMT imaging genetics researches on attention control.