Related Experiment Video
Updated: Jul 7, 2026

The 5-Choice Serial Reaction Time Task: A Task of Attention and Impulse Control for Rodents
Published on: August 10, 2014
Catechol-O-methyltransferase (COMT) val158met genotype is associated with BOLD response as a function of task
Ulrich Ettinger1, Veena Kumari, David A Collier
1King's College London, Centre for Neuroimaging Sciences, Institute of Psychiatry, London, UK. u.ettinger@iop.kcl.ac.uk
Abstract:
The catechol-O-methyltransferase (COMT) val(158)met single nucleotide polymorphism (rs4680) has been shown to be associated with brain activation during a number of neurocognitive and emotional tasks. The present study evaluated genotypic associations with brain function during measurement of cognitive stability (prosaccades) and plasticity (antisaccades). A total of 36 healthy volunteers were genotyped for rs4680 and underwent functional magnetic resonance imaging (fMRI) at 1.5 T. Individuals with at least one val(158) allele (val(158) carriers, N=24) showed lower blood oxygen level-dependent (BOLD) response in ventromedial and dorsomedial prefrontal cortex during antisaccades compared to val(158) noncarriers, whereas met(158) homozygotes (N=12) showed lower BOLD response in a cluster in the posterior cingulate and precuneus during prosaccades compared to val(158) carriers. These findings suggest that associations of COMT val(158)met genotype with brain function may be mediated by task characteristics. The findings may be compatible with a hypothesis on the role of COMT val(158)met genotype in tonic and phasic dopamine levels in brain and differential effects on cognitive measures of stability (eg prosaccades) and plasticity (eg antisaccades).
Related Concept Videos
Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
Human Genetics
The complex relationship between genetics and psychology is observable through common biological components such...
Factors Affecting Drug Response: Overview
Pharmacogenetic Phenotypes: Alterations in Pharmacokinetics, Drug Targets and Biologic Milieu
Dose-Response Relationship: Selectivity and Specificity
Phase II Reactions: Methylation Reactions
The mechanism of methylation unfolds in two stages. The first stage sees a methyltransferase enzyme facilitating the transfer of a methyl group from S-adenosylmethionine (SAM) to the substrate, forming S-adenosylhomocysteine (SAH). The second stage involves further metabolism of SAH into homocysteine, which can be recycled...
