title: Dopamine depletion impairs frontostriatal functional connectivity during a set-shifting task.
abstract: We investigated the effect of transient dopamine depletion on functional connectivity during performance of the Wisconsin Card Sorting Task. Functional magnetic resonance imaging data were analyzed as a psychophysiological interaction, a statistical method used to identify functional connectivity during experimental manipulations. Nineteen healthy subjects were scanned, double blind, on 2 separate days: once after drinking an amino acid mixture deficient in the dopamine precursors tyrosine and phenylalanine, and once after drinking a nutritionally balanced mixture. In the balanced drink session, statistically significant connectivity between the frontal lobes and striatum was observed during set shifting, and the greater the prefrontostriatal connectivity, the faster the response time after a shift. Neither of these associations were observed after dopamine depletion. Moreover, dopamine depletion also reduced the degree of deactivation in areas normally suppressed during attention-demanding tasks, including the medial prefrontal cortex, posterior cingulate cortex, and hippocampus. Together, these results suggest that functional connectivity between the frontal lobes and basal ganglia during set shifting contributes to more efficient performance and that dopamine modulates this corticostriatal connectivity.
authors.affiliation: Montreal Neurological Institute, Montréal, Quebec, Canada H3A 2B4.
authors.forename: Atsuko
authors.initials: A
authors.lastname: Nagano-Saito
authors.forename: Marco
authors.initials: M
authors.lastname: Leyton
authors.forename: Oury
authors.initials: O
authors.lastname: Monchi
authors.forename: Yael K
authors.initials: YK
authors.lastname: Goldberg
authors.forename: Yong
authors.initials: Y
authors.lastname: He
authors.forename: Alain
authors.initials: A
authors.lastname: Dagher
mesh_terms: D000328:Adult; D000596:Amino Acids / Q000097:blood; D001288:Attention / Q000502:physiology*; D001931:Brain Mapping; D003342:Corpus Striatum / Q000098:blood supply / Q000503:physiopathology*; D004298:Dopamine / Q000172:deficiency*; D004311:Double-Blind Method; D005260:Female; D005526:Food, Formulated / Q000009:adverse effects; D005625:Frontal Lobe / Q000098:blood supply / Q000503:physiopathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009434:Neural Pathways / Q000098:blood supply / Q000503:physiopathology; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D011601:Psychophysics; D011930:Reaction Time / Q000502:physiology
chemical_list: D000596:Amino Acids; D010100:Oxygen; D004298:Dopamine