title: Self-administration in rats allowed unlimited access to nicotine.
abstract: The purpose of the present study was to develop an animal model of nicotine self-administration that more closely approximates the conditions of human nicotine use than do existing models. In most nicotine self-administration models, rats acquire self-administration during brief daily sessions in which rapid injections of a relatively high dose of the drug, 0.03 mg/kg, serve as the reinforcer. The present study examined nicotine self-administration in rats that acquired the behavior while having virtually unlimited access to injections of a relatively low dose of the drug; the rats did not have any prior operant training or shaping. Under these conditions, rats readily acquire nicotine self-administration at doses at least as low as 0.00375 mg/kg per injection, and they self-administer throughout the active portion of their light cycle. The daily nicotine intake of rats, which ranged from 0.18 to 1.38 mg/kg per day, appears to be comparable to that of human smokers.
authors.affiliation: Endocrine-Neuroscience Research Laboratories, Minneapolis Medical Foundation, MN 55404, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Valentine
authors.forename: J S
authors.initials: JS
authors.lastname: Hokanson
authors.forename: S G
authors.initials: SG
authors.lastname: Matta
authors.forename: B M
authors.initials: BM
authors.lastname: Sharp
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D008297:Male; D009538:Nicotine / Q000008:administration & dosage / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D012646:Self Administration
chemical_list: D018722:Nicotinic Agonists; D009538:Nicotine