title: Lack of tolerance to nicotine-induced dopamine release in the nucleus accumbens.
abstract: The extent to which repeated administration produces tolerance to nicotine-induced increases in dopamine transmission in the nucleus accumbens was investigated in rats. In vivo microdialysis was used to sample extracellular dopamine and metabolites after a nicotine challenge (0.35 mg/kg) in (1) naive rats, (2) acutely pretreated rats (1 prior nicotine injection), and (3) chronically pretreated rats (12-15 prior daily nicotine injections, 0.35 mg/kg per injection). Nicotine increased extracellular DA and its metabolites, and these increases were not significantly altered by either acute or chronic prior exposure to the drug. The failure to find evidence of tolerance is compatible with the hypothesis that the mesolimbic dopaminergic system is a substrate for the reinforcing properties of chronically administered nicotine.
authors: Department of Psychiatry, University of British Columbia, Vancouver, Canada.
authors: G
authors: G
authors: Damsma
authors: J
authors: J
authors: Day
authors: H C
authors: HC
authors: Fibiger
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003956:Dialysis; D004298:Dopamine / Q000378:metabolism*; D004361:Drug Tolerance; D006168:Guinea Pigs; D006719:Homovanillic Acid / Q000378:metabolism; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D009538:Nicotine / Q000494:pharmacology*; D009714:Nucleus Accumbens / Q000033:anatomy & histology / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012686:Septal Nuclei / Q000378:metabolism*
chemical_list: D015102:3,4-Dihydroxyphenylacetic Acid; D006897:Hydroxyindoleacetic Acid; D009538:Nicotine; D004298:Dopamine; D006719:Homovanillic Acid