title: beta2-Nicotinic acetylcholine receptor availability during acute and prolonged abstinence from tobacco smoking.
abstract: BACKGROUND
  Available levels of nicotinic acetylcholine receptors containing the beta(2) subunit (beta(2)*-nAChR) are higher in recently abstinent tobacco smokers compared with participants who never smoked. Variations in beta(2)*-nAChR availability during the course of abstinence may be related to the urge to smoke, the extent of nicotine withdrawal, and successful abstinence.
  
  
  OBJECTIVE
  To examine changes in beta(2)*-nAChR availability during acute and prolonged abstinence from tobacco smoking and to determine how changes in beta(2)*-nAChR availability were related to clinical features of tobacco smoking.
  
  
  METHODS
  Tobacco smokers participated in up to 4 iodide 123-labeled 5-iodo-A-85380 ([(123)I]5-IA) single-photon emission computed tomography (SPECT) scans during abstinence at 1 day (n = 7) and 1 (n = 17), 2 (n = 7), 4 (n = 11), and 6 to 12 (n = 6) weeks. Age-matched nonsmokers participated in a single [(123)I]5-IA SPECT scan. All participants completed 1 magnetic resonance imaging study.
  
  
  METHODS
  Academic imaging center.
  
  
  METHODS
  Tobacco smokers (n = 19) and an age-matched nonsmoker comparison group (n = 20). Main Outcome Measure The [(123)I]5-IA SPECT images were converted to distribution volume and were analyzed using regions of interest.
  
  
  RESULTS
  Compared with nonsmokers, beta(2)*-nAChR availability in the striatum, cortex, and cerebellum of smokers was not different at 1 day of abstinence, was significantly higher at 1 week of abstinence, and was not different at 4 or at 6 to 12 weeks of abstinence. In smokers, beta(2)*-nAChR availability was significantly lower in the cortex and cerebellum at 6 to 12 weeks compared with 1 week of abstinence. In addition, cerebellar beta(2)*-nAChR availability at 4 weeks of abstinence was positively correlated with craving on the day of the SPECT scan.
  
  
  CONCLUSIONS
  These data suggest that higher beta(2)*-nAChR availability persists up to 1 month of abstinence and normalizes to nonsmoker levels by 6 to 12 weeks of abstinence from tobacco smoking. These marked and persistent changes in beta(2)*-nAChR availability may contribute to difficulties with tobacco cessation.
authors.affiliation: Department of Psychiatry, Yale University School of Medicine, 950 Campbell Ave, Mail Code 116A6, West Haven, CT 06516, USA. kelly.cosgrove@yale.edu
authors.forename: Kelly P
authors.initials: KP
authors.lastname: Cosgrove
authors.forename: Jeffery
authors.initials: J
authors.lastname: Batis
authors.forename: Frederic
authors.initials: F
authors.lastname: Bois
authors.forename: Paul K
authors.initials: PK
authors.lastname: Maciejewski
authors.forename: Irina
authors.initials: I
authors.lastname: Esterlis
authors.forename: Tracy
authors.initials: T
authors.lastname: Kloczynski
authors.forename: Stephanie
authors.initials: S
authors.lastname: Stiklus
authors.forename: Suchitra
authors.initials: S
authors.lastname: Krishnan-Sarin
authors.forename: Stephanie
authors.initials: S
authors.lastname: O'Malley
authors.forename: Edward
authors.initials: E
authors.lastname: Perry
authors.forename: Gilles
authors.initials: G
authors.lastname: Tamagnan
authors.forename: John P
authors.initials: JP
authors.lastname: Seibyl
authors.forename: Julie K
authors.initials: JK
authors.lastname: Staley
mesh_terms: D000328:Adult; D001384:Azetidines; D001921:Brain / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001931:Brain Mapping; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007457:Iodine Radioisotopes; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009538:Nicotine / Q000009:adverse effects; D011978:Receptors, Nicotinic / Q000502:physiology*; D012907:Smoking / Q000503:physiopathology*; D016540:Smoking Cessation / Q000523:psychology*; D013375:Substance Withdrawal Syndrome / Q000000981:diagnostic imaging / Q000503:physiopathology; D014029:Tobacco Use Disorder / Q000000981:diagnostic imaging* / Q000503:physiopathology; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D001384:Azetidines; D007457:Iodine Radioisotopes; D009538:Nicotine; D011978:Receptors, Nicotinic; C104288:A 85380