The impact of Val108/158Met polymorphism of catechol-O-methyltransferase on brain oscillations during working memory

This study investigated whether catechol- O-methyltransferase (COMT) Val/Met polymorphism was associated with variation in event-related desynchronization/synchronization (ERD/ERS) of responses during working memory (WM). 11 Val/Val and 11 Met/Met homozygous participants underwent magnetoencephalography (MEG) while performing a WM task. In contrast to small effects behaviourally, during the delay period Val/Val individuals showed lower ERS in the gamma band (Hz 30-50) in frontal regions, increased ERS in the alpha band (Hz 8-12) in the right frontal and parietal regions and increased ERD in the beta band (Hz 14-30) in the left fronto-temporal regions as compared with Met/Met homozygous individuals. During the response period Val/Val participants showed greater beta ERD in the prefrontal and parietotemporal regions. These results demonstrate that COMT genotype has a strong impact on brain responses (oscillatory activity) during WM performance likely a consequence of compensatory activity during the delay and response periods.