Influence of SLC6A3 and COMT variation on neural activation during response inhibition

There is evidence concerning the neural and genetic correlates of inhibitory control, but there have been limited attempts to combine this information. This study tested the hypothesis that two dopaminergic polymorphisms, SLC6A3 and COMT, influence neural activation during response inhibition. Healthy adults were genotyped for these polymorphisms and performed a measure of response inhibition while undergoing functional magnetic resonance imaging (fMRI). Results support the role of key frontostriatal regions underlying response inhibition. Furthermore, results support a significant influence of SLC6A3 and COMT variants on neural activity during inhibition, with greater activation during inhibition in carriers of the SLC6A3 9-allele or the COMT met-allele as compared to carriers of the SLC6A3 10/10 genotype or the COMT val/val genotype. These results add to a growing literature suggesting that inhibitory control is sensitive to variation in dopamine function, and suggest that this variation may be detectable at the level of individuals' genotypes.