Acute quantitative electroencephalographic effects of cigarette smoking were examined in 15 smokers within a repeated-measures design which assessed changes in power-spectral estimates following acute pre-treatment with placebo, a dose (20 mg) of mecamylamine, a dose (0.6 mg) of scopolamine and a combined dose of mecamylamine and scopolamine. Compared to sham smoking, the smoking of a single cigarette following placebo pre-treatment reduced absolute and relative power in slow (delta, theta) frequency bands, increased absolute and relative power in alpha and beta frequency bands and accelerated mean frequency. These smoking-induced power changes in slow- and fast-frequency bands were differentially affected by the separate and combined actions of the cholinergic antagonists with treatments involving mecamylamine tending to abolish smoking-induced slow-frequency absolute power reductions and fast-frequency relative power increments. Self-ratings of smoking-induced increases in alertness were altered by mecamylamine and combined treatments while sensory aspects of cigarette smoking were only altered with combined mecamylamine and scopolamine pre-treatment. The results are discussed with respect to brain-behaviour relationships and mechanisms maintaining the smoking habit.

As neuroelectric research into the smoking/nicotine habit has focused exclusively on young and middle-aged adults, this electroencephalographic (EEG) study was conducted to determine whether a long-term smoking history alters the aging brain and/or whether the aging brain demonstrates an altered sensitivity to acute smoking/nicotine. Forty healthy adults, 20 young, aged 18-39 years, and 20 elderly, aged 64–81 years, volunteered for participation. Half of the young and elderly were nonsmokers with no previous smoking history and the remaining half of the young and elderly were current smokers with average smoking histories of 9.3 and 52.0 years, respectively. Smokers attended the laboratory for two randomized test sessions during which multisite EEG recordings were collected pre and post sham and cigarette smoking. Nonsmokers attended the laboratory for one nonsmoking EEG recording session. Spectral power indices showed aging to be associated with significant reductions in absolute delta and theta power and increases in relative beta power and faster mean total band frequency. Aging effects varied with recording region but not with smoker versus nonsmoker status. Smokers did exhibit a faster mean beta frequency. Acute cigarette smoking decreased absolute delta power in young smokers and increased relative alpha2, beta power and mean alpha frequency in both young and elderly smokers. Only the young smokers showed increase in mean theta and total frequency. The results are discussed in relation to cognition in normal and pathological aging.

No abstract

As previous research has shown central nicotinic receptors to (a) be asymmetrical, (b) decline with age, and (c) be more abundant in smokers, quantified EEG indices of hemispheric asymmetry were employed to assess whether smoker/non-smoker status affected the aging brain and whether the aging brain demonstrated an altered response to acute smoking/nicotine. Forty healthy volunteers participated, including 20 young (18–39 years) and 20 elderly (64–81 years) adults. Half of the subjects in each age category were lifelong non-smokers and half were cigarette smokers with average smoking histories of 9.3 and 52.0 years for young and elderly respectively. Inter-hemispheric theta and alpha asymmetry indices illustrated greater left hemisphere power (relative to right) in elderly adults, while the reverse trend was seen in young adults. Smokers and non-smokers both showed similar aging trends but differed with respect to their presence in frontal and posterior regions. Intra-hemispheric asymmetry indices, particularly with alpha activity, illustrated a reduced anterior-posterior gradient of power distribution in the elderly. Acute smoking increased slow (delta) and fast (beta) inter-hemispheric indices but only in elderly smokers. Smoking also altered the intra-hemispheric balance of slow wave activity in both age groups of smokers. The results are discussed in relation to normal and pathological aging.