RT Journal
A1 Brody AL, Mandelkern MA, London ED, et al
T1 EFfect of secondhand smoke on occupancy of nicotinic acetylcholine receptors in brain
JF Archives of General Psychiatry
JO Archives of General Psychiatry
YR 2011
FD September 1
VO 68
IS 9
SP 953
OP 960
DO 10.1001/archgenpsychiatry.2011.51
UL http://dx.doi.org/10.1001/archgenpsychiatry.2011.51
AB Context 
                  Despite progress in tobacco control, secondhand smoke (SHS) exposure remains prevalent worldwide and is implicated in the initiation and maintenance of cigarette smoking.Objective 
                  To determine whether moderate SHS exposure results in brainα4β2* nicotinic acetylcholine receptor (nAChR) occupancy.Design, Setting, and Participants 
                  Positron emission tomography scanning and the radiotracer 2-[18F]fluoro-3-(2(S)azetidinylmethoxy) pyridine (also known as 2-[18F]fluoro-A-85380, or 2-FA) were used to determineα4β2* nAChR occupancy from SHS exposure in 24 young adult participants (11 moderately dependent cigarette smokers and 13 nonsmokers). Participants underwent two bolus-plus-continuous-infusion 2-FA positron emission tomography scanning sessions during which they sat in the passenger's seat of a car for 1 hour and either were exposed to moderate SHS or had no SHS exposure. The study took place at an academic positron emission tomography center.Main Outcome Measure 
                  Changes induced by SHS in 2-FA specific binding volume of distribution as a measure ofα4β2* nAChR occupancy.Results 
                  An overall multivariate analysis of variance using specific binding volume of distribution values revealed a significant main effect of condition (SHS vs control) (F1,22 = 42.5, P < .001) but no between-group (smoker vs nonsmoker) effect. Exposure to SHS led to a mean 19% occupancy of brainα4β2* nAChRs (1-sample t test, 2-tailed, P < .001). Smokers had both a mean 23% increase in craving with SHS exposure and a correlation between thalamicα4β2* nAChR occupancy and craving alleviation with subsequent cigarette smoking (Spearmanρ = −0.74, P = .01).Conclusions 
                  Nicotine from SHS exposure results in substantial brainα4β2* nAChR occupancy in smokers and nonsmokers. Study findings suggest that such exposure delivers a priming dose of nicotine to the brain that contributes to continued cigarette use in smokers. This study has implications for both biological research into the link between SHS exposure and cigarette use and public policy regarding the need to limit SHS exposure in cars and other enclosed spaces.