title: Acute nicotine differentially impacts anticipatory valence- and magnitude-related striatal activity.
abstract: BACKGROUND
  Dopaminergic activity plays a role in mediating the rewarding aspects of abused drugs, including nicotine. Nicotine modulates the reinforcing properties of other motivational stimuli, yet the mechanisms of this interaction are poorly understood. This study aimed to ascertain the impact of nicotine exposure on neuronal activity associated with reinforcing outcomes in dependent smokers.
  
  
  METHODS
  Smokers (n = 28) and control subjects (n = 28) underwent functional imaging during performance of a monetary incentive delay task. Using a randomized, counterbalanced design, smokers completed scanning after placement of a nicotine or placebo patch; nonsmokers were scanned twice without nicotine manipulation. In regions along dopaminergic pathway trajectories, we considered event-related activity for valence (reward/gain vs. punishment/loss), magnitude (small, medium, large), and outcome (successful vs. unsuccessful).
  
  
  RESULTS
  Both nicotine and placebo patch conditions were associated with reduced activity in regions supporting anticipatory valence, including ventral striatum. In contrast, relative to controls, acute nicotine increased activity in dorsal striatum for anticipated magnitude. Across conditions, anticipatory valence-related activity in the striatum was negatively associated with plasma nicotine concentration, whereas the number of cigarettes daily correlated negatively with loss anticipation activity in the medial prefrontal cortex only during abstinence.
  
  
  CONCLUSIONS
  These data suggest a partial dissociation in the state- and trait-specific effects of smoking and nicotine exposure on magnitude- and valence-dependent anticipatory activity within discrete reward processing brain regions. Such variability may help explain, in part, nicotine's impact on the reinforcing properties of nondrug stimuli and speak to the continued motivation to smoke and cessation difficulty.
authors.affiliation: Neuroimaging Research Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD 21228, USA. emmajanerose@gmail.com
authors.forename: Emma Jane
authors.initials: EJ
authors.lastname: Rose
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Ross
authors.forename: Betty Jo
authors.initials: BJ
authors.lastname: Salmeron
authors.forename: Mary
authors.initials: M
authors.lastname: Lee
authors.forename: Diaa M
authors.initials: DM
authors.lastname: Shakleya
authors.forename: Marilyn A
authors.initials: MA
authors.lastname: Huestis
authors.forename: Elliot A
authors.initials: EA
authors.lastname: Stein
mesh_terms: D000279:Administration, Cutaneous; D000328:Adult; D001931:Brain Mapping; D003342:Corpus Striatum / Q000187:drug effects* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009042:Motivation; D009538:Nicotine / Q000008:administration & dosage*; D012907:Smoking / Q000503:physiopathology*; D014029:Tobacco Use Disorder / Q000503:physiopathology*
chemical_list: D009538:Nicotine