Positron emission tomography (PET) has convincingly provided in vivo evidence that psychoactive drugs increase dopamine (DA) levels in human brain, a feature thought critical to their reinforcing properties. Some controversy still exists concerning the role of DA in reinforcing smoking behavior and no study has explored whether smoking increases DA concentrations at the D3 receptor, speculated to have a role in nicotine's addictive potential. Here, we used PET and [(11)C]-(+)-PHNO ([(11)C]-(+)-4-propyl-3,4,4a,5,6,10b-hexahydro-2H-naphtho[1,2-b][1,4]oxazin-9-ol) to test the hypothesis that smoking increases DA release (decreases [(11)C]-(+)-PHNO binding) in D2-rich striatum and D3-rich extra-striatal regions and is related to craving, withdrawal and smoking behavior.
View Article and Find Full Text PDFThe presentation of drug-associated cues has been shown to elicit craving and dopamine release in the striatum of drug-dependent individuals. Similarly, exposure to tobacco-associated cues induces craving and increases the propensity to relapse in tobacco- dependent smokers. However, whether exposure to tobacco-associated cues elicits dopamine release in the striatum of smokers remains to be investigated.
View Article and Find Full Text PDFRationale: Neuronal nicotinic acetylcholine receptors (nAChRs) are pharmacological targets that have recently been implicated in the reinforcing effects of many drugs of abuse, including ethanol. Varenicline and cytisine are nAChR partial agonists in clinical use as smoking cessation aids. However, their efficacies to reduce alcohol consumption have not been fully studied.
View Article and Find Full Text PDFBackground: Relapse is a serious challenge in problem gambling (PG), as it is in substance addiction. Stress and cues are implicated in relapse in both conditions. However, experimental research on motivational effects of stress in PG subjects is scant.
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