Brain activity changes (measured with fMRI) during cigarette withdrawal were recently reported for nicotine-dependent rats (Shoaib et al. 2004). In this study, subcutaneous mecamylamine (1 mg kg−1), a nicotine receptor antagonist, was administered to precipitate withdrawal during scanning, and this state was compared to a control state after subcutaneous saline administration. After subcutaneous mecamy-lamine, nicotine-dependent rats had bilateral increases in NAc activity compared to the control state.
