title: Impact of smoking abstinence on working memory neurocircuitry in adolescent daily tobacco smokers.
abstract: BACKGROUND
  Efficient function of neurocircuitry that supports working memory occurs within a narrow range of dopamine neurotransmission. Work in rodents has shown that exposure to nicotine during adolescence leads to nicotine withdrawal emergent alterations in cortical and subcortical dopamine neurotransmission.
  
  
  OBJECTIVE
  To test for evidence that the efficiency of neurocircuitry supporting working memory is altered during acute smoking abstinence in adolescent daily tobacco smokers.
  
  
  METHODS
  Fifty-five adolescent daily tobacco smokers were compared with 38 nonsmokers using functional magnetic resonance imaging while subjects performed a verbal working memory task. Smokers were studied during smoking and after 24 h of abstinence from tobacco use.
  
  
  RESULTS
  Performance of a task with high working memory load in the context of smoking abstinence was associated with greater activation of components of the verbal working memory neurocircuit, including left ventrolateral prefrontal cortex and left inferior parietal lobe, among smokers relative to nonsmokers. During smoking abstinence, smokers failed to exhibit increases in functional connectivity between components of the working memory neurocircuit with increasing working memory load observed in nonsmoking adolescents and in prior studies of adults.
  
  
  CONCLUSIONS
  Smoking abstinence in adolescent smokers is associated with reductions in the efficiency of working memory neurocircuitry and alterations in the functional coordination between components of the working memory neurocircuit. These alterations may stem from effects of nicotine exposure on catecholaminergic systems during adolescent development.
authors.affiliation: Department of Psychiatry, Yale University School of Medicine, 2 Church Street South, Suite 207, New Haven, CT 06519, USA. leslie.jacobsen@yale.edu
authors.forename: Leslie K
authors.initials: LK
authors.lastname: Jacobsen
authors.forename: W Einar
authors.initials: WE
authors.lastname: Mencl
authors.forename: R Todd
authors.initials: RT
authors.lastname: Constable
authors.forename: Michael
authors.initials: M
authors.lastname: Westerveld
authors.forename: Kenneth R
authors.initials: KR
authors.lastname: Pugh
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D010296:Parietal Lobe / Q000502:physiology; D017397:Prefrontal Cortex / Q000502:physiology; D012907:Smoking; D016540:Smoking Cessation