Smoking-Induced Ventral Striatum Dopamine Release

Abstract

OBJECTIVE: Substantial evidence from animal models demonstrates that dopamine release in the ventral striatum underlies the reinforcing properties of nicotine. The authors used [11C]raclopride bolus-plus-continuous-infusion positron emission tomography (PET) to determine smoking-induced ventral striatum dopamine release in humans. METHOD: Twenty nicotine-dependent smokers (who smoked ≥15 cigarettes/day) underwent a [11C]raclopride bolus-plus-continuous-infusion PET session. During the session, subjects had a 10-minute break outside the PET apparatus during which 10 subjects smoked a cigarette and 10 did not smoke (as a control condition). RESULTS: The group that smoked had greater reductions in [11C]raclopride binding potential in ventral striatum regions of interest than the group that did not smoke, particularly in the left ventral caudate/nucleus accumbens and left ventral putamen (range for smoking group=–25.9% to –36.6% reduction). Significant correlations were found between change from before to aft...