| Acute cigarette smoking induces self-reported arousal increments and a characteristic stimulant-like EEG response profile consisting of amplitude reductions in slow (delta, theta) wave frequencies and amplitude increases in fast (alpha, beta) wave frequencies. Given the dependence-producing nature of smoke-inhaled nicotine and the role of the dopaminergic system in drug dependencies, this study examined the role of dopamine in modulating the smoking-induced activation response. In a randomized, double-blind, repeated measures design, quantitative electroencephalographic (EEG) changes and self-reports induced by the smoking of a single cigarette were assessed following pretreatment with placebo and haloperidol (2 mg), a dopamine antagonist. Following placebo pretreatment, absolute (muV) and relative (%) amplitude slow frequency bands (delta, theta, alpha,) were reduced and absolute (muV) and relative (%) amplitude fast frequency bands (alpha2, beta) were increased following cigarette smoking as compared to sham smoking. Haloperidol pretreatment inhibited the smoking-induced increase in absolute beta frequency. Self-ratings indicated that cigarette smoking induced increases in alertness, contentedness, calmness, and euphoria and reduced cigarette cravings as compared to the sham smoking condition. Smoking-related self-ratings were not altered by haloperidol, but subjects were less content overall in the haloperidol condition as compared to placebo. Discussion of these results focus on transmitter systems and their relationship to neuroelectric and behavioural activities associated with the smoking habit. |
