title: Nicotine related brain activity: the influence of smoking history and blood nicotine levels, an exploratory study.
abstract: OBJECTIVE
  In this study, we sought to explore brain activity in nicotine-dependent men in response to acute intravenous nicotine using pharmacological magnetic resonance imaging (phMRI).
  
  
  METHODS
  phMRI was used to evaluate brain activity in response to 1.5 mg/70 kg intravenous nicotine or saline. The nicotine and saline were administered on different visits. The time courses of individual subjects' nicotine levels were used as regressors to assess neural activity relating to the infusions. The influence of smoking history and physiological measures on the response to nicotine were also investigated.
  
  
  RESULTS
  Greater lifetime exposure to cigarette smoking was significantly correlated with higher peak serum nicotine levels. PhMRI analysis of the differential response of nicotine compared to the saline condition showed distinctive activation patterns when analyzed with the (a) nicotine time course, (b) nicotine time course controlling for smoking history (pack years), and (c) pack years controlling for nicotine.
  
  
  CONCLUSIONS
  These results suggest that smoking exposure history influences serum nicotine levels and the brain's response to nicotine. Alterations in brain activity may be a result of vascular and neuro-adaptations involved in drug exposure and addiction.
authors.affiliation: Brain Imaging Center, McLean Hospital, Harvard Medical School, 115 Mill St., Belmont, MA 02478, United States. yamamoto@mclean.harvard.edu
authors.forename: Rinah T
authors.initials: RT
authors.lastname: Yamamoto
authors.forename: Michael L
authors.initials: ML
authors.lastname: Rohan
authors.forename: Nathalie
authors.initials: N
authors.lastname: Goletiani
authors.forename: David
authors.initials: D
authors.lastname: Olson
authors.forename: MacKenzie
authors.initials: M
authors.lastname: Peltier
authors.forename: Perry F
authors.initials: PF
authors.lastname: Renshaw
authors.forename: Nancy K
authors.initials: NK
authors.lastname: Mello
mesh_terms: D000328:Adult; D001921:Brain / Q000187:drug effects*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009538:Nicotine / Q000097:blood* / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000097:blood* / Q000494:pharmacology*; D010100:Oxygen / Q000097:blood; D012907:Smoking / Q000503:physiopathology*; D055815:Young Adult
chemical_list: D018722:Nicotinic Agonists; D009538:Nicotine; D010100:Oxygen