The cholinergic basis of the smoking-induced EEG activation profile.
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.
Knott
V J
VJ
Department of Psychiatry, University of Ottawa/Royal Ottawa Hospital and Institute of Mental Health Research, Ottawa, Ont., Canada. V.Knott@rohcg.on.ca
Harr
A
A
Ilivitsky
V
V
Mahoney
C
C
D000328:Adult; D000704:Analysis of Variance; D001143:Arousal / Q000187:drug effects / Q000502:physiology; D002540:Cerebral Cortex / Q000187:drug effects* / Q000502:physiology; D002799:Cholinergic Fibers / Q000187:drug effects / Q000502:physiology*; D004569:Electroencephalography; D006801:Humans; D008297:Male; D008464:Mecamylamine; D008875:Middle Aged; D018727:Muscarinic Antagonists; D009538:Nicotine / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000494:pharmacology*; D018733:Nicotinic Antagonists; D012601:Scopolamine; D012677:Sensation / Q000187:drug effects / Q000502:physiology; D012907:Smoking / Q000503:physiopathology* / Q000523:psychology
D018727:Muscarinic Antagonists; D018722:Nicotinic Agonists; D018733:Nicotinic Antagonists; D008464:Mecamylamine; D009538:Nicotine; D012601:Scopolamine