The Effects of Smoking Withdrawal On Resting State Functional Connectivity (SmokeAtt04)

• Blood-oxygen-level-dependent (BOLD) signal [ Time Frame: following smoking cigarette 30 minutes prior to scan ] [ Designated as safety issue: No ]
  Smokers will be scanned after smoking to satiety. In order to be considered satiated, smokers will have to be regular smokers (smoking daily for at least 2 years).
  
  

• Blood-oxygen-level-dependent (BOLD) signal [ Time Frame: 24 hours abstinence ] [ Designated as safety issue: No ]
  Smokers will be asked to stop smoking 24 hours prior to the scan without the aid of nicotine replacement therapies. They will resume smoking as usual 24 hours after the scan.
  
  

Behavioral: Abstain from smoking for 24 hours
Compare smoking satiation to 24 hour smoking abstinence

The broad objective of this proposal is to identify functional neuroanatomical correlates of changes in brain functional connectivity during smoking abstinence. The investigators will measure changes in regional blood oxygenation levels using fMRI while adult smokers and non-smokers lie in the scanner with their eyes closed. Smokers will be scanned when they are abstinent from smoking for 24 hrs and shortly after smoking. Our primary hypothesis is that smoking abstinence will alter resting state brain activity (or resting state functional connectivity; RSFC) across widely distributed neural networks and that high-resolution fMRI will help in resolving the exact nature of such changes. Data will be analyzed using methods developed in our laboratory and applied to other resting state datasets. All of the procedures used in the study are well validated and introduce only minor risk to participants (e.g. blood draw; MRI).