Chunk #18 — Neurocognitive and Neurobiological Effects of Acute Nicotine Exposure and Withdrawal — Acute Nicotine Consumption, Nicotine Withdrawal and Neurobiological Function
Several functional neuroimaging (PET, SPECT, fMRI) studies in active chronic smokers (see [21,22] for review) and a few functional MRI studies addressed the acute effects of nicotine administration on brain activity during task activation in healthy non-smokers [17,18,20]. The effects of acute cigarette smoking on functional neuroimaging modalities in non-smokers have not been investigated [18,20]. In chronic smokers, functional neuroimaging studies investigating responses to acute smoking or nicotine administration have shown are that acute nicotine administration is associated with decreased global cerebral blood flow, increased activity in the dorsolateral, inferior and mesial frontal and orbitofrontal regions, thalamus and visual processing regions (see [21,22]). In chronic smokers deprived of tobacco for more than 2 hours, acute cigarette smoking elicits different patterns of relative perfusion responses, with increases of the order of 6–8% in the anterior frontal and cingulate cortices as well as decreases in cerebellum and occipital lobes that were associated with plasma nicotine levels [18,114,115]. Some studies report a 7–10% decrease in global glucose utilization following acute nicotine administration in chronic smokers deprived of nicotine for 8 hours or more
