Dopamine transporter genotype modulates brain activity during a working memory task in children with ADHD

Publication date: September 2019Source: Research in Developmental Disabilities, Volume 92Author(s): Guillaume Pineau, Thomas Villemonteix, Hichem Slama, Martin Kavec, Danielle Balériaux, Thierry Metens, Simon Baijot, Alison Mary, Nicolas Ramoz, Philip Gorwood, Philippe Peigneux, Isabelle MassatAbstractDopamine active transporter gene (DAT1) is a candidate gene associated with attention-deficit/hyperactivity disorder (ADHD). The DAT1 variable number tandem repeat (VNTR)-3’ polymorphism is functional and 9R carriers have been shown to produce more DAT than 10R homozygotes. We used functional magnetic resonance imaging (fMRI) to investigate the effects of this polymorphism on the neural substrates of working memory (WM) in a small but selected population of children with ADHD, naïve of any psychotropic treatment and without comorbidity. MRI and genotype data were obtained for 36 children (mean age: 10,36 +/− 1,49 years) with combined-type ADHD (9R n = 15) and 25 typically developing children (TDC) (mean age: 9,55 +/− 1,25 years) (9R n = 12). WM performance was similar between conditions. We found a cross-over interaction effect between gene (9R vs. 10R) and diagnosis (TDC vs. ADHD) in the orbito-frontal gyrus, cerebellum and inferior temporal lobe. In these areas, WM-related activity was higher for 9R carriers in ADHD subjects and lower in TDC. In ADHD children only, 10R homozygotes exhibited higher WM-related activity than 9R carriers in a network encompassing t...
Source: Research in Developmental Disabilities - Category: Disability Source Type: research