title: The effects of DAT1 genotype on fMRI activation in an emotional go/no-go task.
abstract: Dopaminergic brain circuits participate in emotional processing and impulsivity. The dopamine transporter (DAT) modulates dopamine reuptake. A variable number tandem repeat (VNTR) in the dopamine transporter gene (DAT1) affects DAT expression. The influence of DAT1 genotype on neural activation during emotional processing and impulse inhibition has not been examined. Forty-two healthy subjects were classified as 9DAT (n = 17) or 10DAT (n = 25) based on DAT1 genotype (9DAT = 9R/9R and 9R/10R; 10DAT = 10R/10R). Subjects underwent fMRI during non-emotional and emotional go/no-go tasks. Subjects were instructed to inhibit responses to letters, happy faces, or sad faces in separate blocks. Accuracy and reaction time did not differ between groups. Within group results showed activation in regions previously implicated in emotional processing and response inhibition. Between groups results showed increased activation in 9DAT individuals during inhibition. During letter inhibition, 9DAT individuals exhibited greater activation in right inferior parietal regions. During sad inhibition, 9DAT Individuals exhibited greater activation in frontal, posterior cingulate, precuneus, right cerebellar, left paracentral, and right occipital brain regions. The interaction between DAT genotype and response type in sad versus letter stimuli showed increased activation in 9DAT individuals during sad no-go responses in the anterior cingulate cortex, extending into frontal-orbital regions. 9DAT individuals have greater activation than 10DAT individuals during neutral and sad inhibition, showing that genotypic variation influencing basal dopamine levels can alter the neural basis of emotional processing and response inhibition. This may indicate that 9R carriers exert more effort to overcome increased basal dopamine activation when inhibiting responses in emotional contexts.
authors: Case Western Reserve University School of Medicine, Cleveland, OH, USA.
authors: Brenna K
authors: BK
authors: Brown
authors: Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN, USA.
authors: Jill
authors: J
authors: Murrell
authors: Center for Behavioral Health, Cleveland Clinic, 9500 Euclid Avenue P57, Cleveland, OH, 44122, USA.
authors: Harish
authors: H
authors: Karne
authors: Center for Behavioral Health, Cleveland Clinic, 9500 Euclid Avenue P57, Cleveland, OH, 44122, USA. ananda@ccf.org.
authors: Amit
authors: A
authors: Anand
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000502:physiology*; D050483:Dopamine Plasma Membrane Transport Proteins / Q000235:genetics*; D004644:Emotions / Q000502:physiology*; D056344:Executive Function / Q000502:physiology*; D000066499:Facial Recognition / Q000502:physiology; D005260:Female; D060005:Genotyping Techniques; D006579:Heterozygote; D006801:Humans; D007175:Impulsive Behavior / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D009483:Neuropsychological Tests; D055815:Young Adult
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins; C493214:SLC6A3 protein, human
keywords: Dopamine transporter; Emotion; Response inhibition