title: Influence of COMT Genotype on Antero-posterior Cortical Functional Connectivity Underlying Interference Resolution.
abstract: Genetic variability related to the catechol-O-methyltransferase (COMT) gene (Val(158)Met) has received increasing attention as a possible modulator of executive functioning and its neural correlates. However, this attention has generally centered on the prefrontal cortices because of the well-known direct impact of COMT enzyme on these cerebral regions. In this study, we were interested in the modulating effect of COMT genotype on anterior and posterior brain areas underlying interference resolution during a Stroop task. More specifically, we were interested in the functional connectivity between the right inferior frontal operculum (IFop), an area frequently associated with inhibitory efficiency, and posterior brain regions involved in reading/naming processes (the 2 main non-executive determinants of the Stroop effect). The Stroop task was administered during functional magnetic resonance imaging scanning to 3 groups of 15 young adults divided according to their COMT Val(158)Met genotype [Val/Val (VV), Val/Met (VM), and Met/Met (MM)]. Results indicate greater activity in the right IFop and the left middle temporal gyrus in homozygous VV individuals than in Met allele carriers. In addition, the VV group exhibited stronger positive functional connectivity between these 2 brain regions and stronger negative connectivity between the right IFop and left lingual gyrus. These results confirm the impact of COMT genotype on frontal functions. They also strongly suggest that differences in frontal activity influence posterior brain regions related to a non-executive component of the task. Particularly, changes in functional connectivity between anterior and posterior brain areas might correspond to compensatory processes for performing the task efficiently when the available dopamine level is low.
authors.affiliation: Cyclotron Research Centre.|Department of Psychology: Cognition and Behaviour.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Jaspar
authors.affiliation: Cyclotron Research Centre.|Department of Psychology: Cognition and Behaviour.|Department Genetics, University of Liège, Liège, Belgium.
authors.forename: Marine
authors.initials: M
authors.lastname: Manard
authors.affiliation: Department Genetics, University of Liège, Liège, Belgium.
authors.forename: Vinciane
authors.initials: V
authors.lastname: Dideberg
authors.affiliation: Department Genetics, University of Liège, Liège, Belgium.
authors.forename: Vincent
authors.initials: V
authors.lastname: Bours
authors.affiliation: Cyclotron Research Centre.
authors.forename: Pierre
authors.initials: P
authors.lastname: Maquet
authors.affiliation: Cyclotron Research Centre.|Department of Psychology: Cognition and Behaviour.
authors.forename: Fabienne
authors.initials: F
authors.lastname: Collette
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001931:Brain Mapping / Q000379:methods; D002394:Catechol O-Methyltransferase / Q000235:genetics*; D002540:Cerebral Cortex / Q000098:blood supply / Q000502:physiology*; D056344:Executive Function / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000235:genetics; D005838:Genotype; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009415:Nerve Net / Q000098:blood supply / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D011930:Reaction Time / Q000235:genetics; D055815:Young Adult
chemical_list: C588010:COMT protein, human; D002394:Catechol O-Methyltransferase; D010100:Oxygen
keywords: COMT gene; Stroop task; fMRI; inhibition