title: Nicotine produces long-term increases in cocaine reinforcement in adolescent but not adult rats.
abstract: Studies have shown that many smokers begin using nicotine during adolescence, yet the influence of early nicotine use on the response to other drugs of abuse in adulthood is not fully understood. In the current study, nicotine was administered to adolescent and adult rats for seven days. Thirty days later, cocaine-induced locomotor activity and cocaine self-administration were examined when the rats pretreated as adolescents were adults. Rats exposed to nicotine during early adolescence were sensitized thirty days later to the locomotor-activating effects of cocaine and self-administered a greater number of cocaine infusions than adolescent rats pretreated with vehicle. As a result of this increased intake, the cocaine self-administration dose-response curve was shifted upward indicating an increase in cocaine reinforcement. Rats pretreated with nicotine as adults, however, did not show a difference in locomotor activity or cocaine self-administration thirty days later compared to adult rats pretreated with vehicle. These findings suggest that early exposure to nicotine has long-term consequences on cocaine use. These data further suggest that nicotine use may carry a greater risk during adolescence than adulthood and adolescents who smoke may be particularly vulnerable to stimulant use. This article is part of a Special Issue entitled SI: Adolescent plasticity.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, University of Miami School of Medicine, 1600 NW 10th Avenue, Rm 7096 (D-80), Miami, FL 33136, USA.
authors.forename: Stephanie Collins
authors.initials: SC
authors.lastname: Reed
authors.affiliation: Department of Psychiatry and Behavioral Sciences, University of Miami School of Medicine, 1600 NW 10th Avenue, Rm 7096 (D-80), Miami, FL 33136, USA. Electronic address: sizenwasser@med.miami.edu.
authors.forename: Sari
authors.initials: S
authors.lastname: Izenwasser
mesh_terms: D000375:Aging / Q000187:drug effects* / Q000502:physiology / Q000523:psychology; D000818:Animals; D003042:Cocaine / Q000008:administration & dosage; D019970:Cocaine-Related Disorders / Q000503:physiopathology* / Q000523:psychology; D004195:Disease Models, Animal; D018765:Dopamine Uptake Inhibitors / Q000008:administration & dosage; D004357:Drug Synergism; D008297:Male; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D009538:Nicotine / Q000494:pharmacology; D018722:Nicotinic Agonists / Q000494:pharmacology; D017207:Rats, Sprague-Dawley; D012054:Reinforcement, Psychology; D012646:Self Administration; D012741:Sexual Maturation; D013997:Time Factors; D014029:Tobacco Use Disorder / Q000503:physiopathology* / Q000523:psychology
chemical_list: D018765:Dopamine Uptake Inhibitors; D018722:Nicotinic Agonists; D009538:Nicotine; D003042:Cocaine
keywords: Adolescence; Cocaine; Locomotor activity; Nicotine; Self-administration