Nicotine as a typical drug of abuse in experimental animals and humans.
BACKGROUND
Tobacco use through cigarette smoking is the leading preventable cause of death in the developed world. Nicotine, a psychoactive component of tobacco, appears to play a major role in tobacco dependence, but reinforcing effects of nicotine often are difficult to demonstrate directly in controlled laboratory studies with animal or human subjects.


OBJECTIVE
To review the major findings obtained with various procedures developed to study dependence-related behavioral effects of nicotine in experimental animals and humans, i.e., drug self-administration, conditioned place preference, subjective reports of nicotine effects and nicotine discrimination, withdrawal signs, and ratings of drug withdrawal.


RESULTS
Nicotine can function as an effective reinforcer of drug-seeking and drug-taking behavior both in experimental animals and humans under appropriate conditions. Interruption of chronic nicotine exposure produces withdrawal symptoms that may contribute to relapse. Difficulties encountered in demonstrating reinforcing effects of nicotine under some conditions, relative to other drugs of abuse, may be due to weaker primary reinforcing effects of nicotine or to a more critical contribution of environmental stimuli to the maintenance of drug-seeking and drug-taking behavior with nicotine than with other drugs of abuse. Further experiments are also needed to delineate the role other chemical substances inhaled along with nicotine in tobacco smoke play in sustaining smoking behavior.


CONCLUSIONS
Nicotine acts as a typical drug of abuse in experimental animals and humans.
Le Foll
Bernard
B
Preclinical Pharmacology Section, Behavioral Neuroscience Research Branch, National Institute on Drug Abuse, National Institutes of Health, Department of Health and Human Services, Baltimore, MD 21224, USA. blefoll@intra.nida.nih.gov
Goldberg
Steven R
SR
D000818:Animals; D003216:Conditioning, Operant; D004195:Disease Models, Animal; D006801:Humans; D009538:Nicotine / Q000008:administration & dosage / Q000009:adverse effects*; D012008:Recurrence; D012054:Reinforcement, Psychology; D012907:Smoking / Q000523:psychology*; D016540:Smoking Cessation / Q000523:psychology; D013375:Substance Withdrawal Syndrome / Q000523:psychology*; D014029:Tobacco Use Disorder / Q000523:psychology*
D009538:Nicotine