title: L-DOPA disrupts activity in the nucleus accumbens during reversal learning in Parkinson's disease.
abstract: Evidence indicates that dopaminergic medication in Parkinson's disease may impair certain aspects of cognitive function, such as reversal learning. We used functional magnetic resonance imaging in patients with mild Parkinson's disease to investigate the neural site at which L-DOPA acts during reversal learning. Patients were scanned both ON and OFF their normal dopamine-enhancing L-DOPA medication during the performance of a probabilistic reversal learning task. We demonstrate that L-DOPA modulated reversal-related activity in the nucleus accumbens, but not in the dorsal striatum or the prefrontal cortex. These data concur with evidence from studies with experimental animals and indicate an important role for the human nucleus accumbens in the dopaminergic modulation of reversal learning.
authors.affiliation: Department of Experimental Psychology, Behavioural and Clinical Neurosciences Institute, University of Cambridge, Cambridge, UK. roshan.cools@gmail.com
authors.forename: Roshan
authors.initials: R
authors.lastname: Cools
authors.forename: Simon J G
authors.initials: SJ
authors.lastname: Lewis
authors.forename: Luke
authors.initials: L
authors.lastname: Clark
authors.forename: Roger A
authors.initials: RA
authors.lastname: Barker
authors.forename: Trevor W
authors.initials: TW
authors.lastname: Robbins
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007980:Levodopa / Q000494:pharmacology* / Q000627:therapeutic use; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009714:Nucleus Accumbens / Q000098:blood supply / Q000187:drug effects*; D010100:Oxygen / Q000097:blood; D010300:Parkinson Disease / Q000188:drug therapy / Q000503:physiopathology*; D017397:Prefrontal Cortex / Q000098:blood supply / Q000187:drug effects; D012193:Reversal Learning / Q000187:drug effects*
chemical_list: D007980:Levodopa; D010100:Oxygen