ADHD candidate gene (DRD4 exon III) affects inhibitory control in a healthy sample

作者：Kraemer Ulrike M; Rojo Nuria; Schuele Rebecca; Cunillera Toni; Schoels Ludger; Marco Pallares Josep; Cucurell David; Camara Estela; Rodriguez Fornells Antoni; Muente Thomas F

来源：BMC Neuroscience, 2009, 10(1): 150.

DOI：10.1186/1471-2202-10-150

Background
Dopamine is believed to be a key neurotransmitter in the development of attention-deficit/hyperactivity disorder (ADHD). Several recent studies point to an association of the dopamine D4 receptor (DRD4) gene and this condition. More specifically, the 7 repeat variant of a variable number of tandem repeats (VNTR) polymorphism in exon III of this gene is suggested to bear a higher risk for ADHD. In the present study, we investigated the role of this polymorphism in the modulation of neurophysiological correlates of response inhibition (Go/Nogo task) in a healthy, high-functioning sample.
Results
Homozygous 7 repeat carriers showed a tendency for more accurate behavior in the Go/Nogo task compared to homozygous 4 repeat carriers. Moreover, 7 repeat carriers presented an increased nogo-related theta band response together with a reduced go-related beta decrease.
Conclusions
These data point to improved cognitive functions and prefrontal control in the 7 repeat carriers, probably due to the D4 receptor's modulatory role in prefrontal areas. The results are discussed with respect to previous behavioral data on this polymorphism and animal studies on the impact of the D4 receptor on cognitive functions.

• 出版日期2009-12-20