Operant responding for a visual reinforcer in rats is enhanced by noncontingent nicotine: implications for nicotine self-administration and reinforcement |
| |
Authors: | Eric?C?Donny Nadia?Chaudhri Email author" target="_blank">Anthony?R?CaggiulaEmail author F?Fay?Evans-Martin Sheri?Booth Maysa?A?Gharib Laure?A?Clements Alan?F?Sved |
| |
Institution: | (1) Department of Psychiatry, Behavioral Pharmacology Research Unit, Johns Hopkins University School of Medicine, Baltimore, Md., USA;(2) Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pa., USA;(3) Department of Psychology, University of Pittsburgh, 3131 Sennott Square, 210 Bouquet Street, Pittsburgh, PA 15260, USA |
| |
Abstract: | Rationale Current conceptualizations of drug reinforcement assume that drug-taking behavior is a consequence of the contingent, temporal
relationship between the behavior and drug reward. However, stimulant drugs also potentiate the rewarding effects of other
reinforcers when administered noncontingently.
Objectives These studies were designed to determine whether noncontingent nicotine enhances the reinforcing properties of a nonpharmacological
reinforcer and whether this direct effect facilitates operant behavior within the context of a nicotine self-administration
procedure.
Methods Rats self-administered nicotine or food, or received noncontingent nicotine, saline, or food either with or without a response-contingent,
unconditioned reinforcing visual stimulus (VS).
Results Noncontingent nicotine, whether delivered as discrete injections based on a pattern of self-administered nicotine or as a
continuous infusion, increased response rates maintained by the VS. There were no significant differences in responding by
animals that received contingent compared with noncontingent nicotine when a VS was available. This increase was not observed
in the absence of the VS or as a consequence of noncontingent food delivery. Operant behavior was equally attenuated and reinstated
by the removal and subsequent replacement of contingent and noncontingent nicotine. Nicotine supported self-administration
in the absence of response-contingent, nicotine-paired stimuli; however, response rates were drastically reduced compared
with nicotine self-administration with the VS.
Conclusions Nicotine influences operant behavior in two ways: by acting as a primary reinforcer when it is contingent upon behavior, and
by directly potentiating the reinforcing properties of other stimuli through a nonassociative mechanism. Nicotine self-administration
and smoking may be largely dependent upon this later action.
This work was supported by National Institute on Drug Abuse research grants, DA-10464 and DA-12655. "Principles of laboratory
animal care" (NIH No. 85-23, revised 1985) were followed throughout all experiments. This research was approved by the University
of Pittsburgh Institutional Animal Care and Use Committee, Assurance Number A3187-01 |
| |
Keywords: | Nicotine Self-administration Contingency Reinforcement Extinction Acquisition |
本文献已被 PubMed SpringerLink 等数据库收录! |
|