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Updated: Aug 30, 2026
A Method for Evaluating the Reinforcing Properties of Ethanol in Rats without Water Deprivation, Saccharin Fading or Extended Access Training
Published on: January 29, 2017
Ethanol-reinforced behaviour predicts acquisition but not extinction of cocaine self-administration in the rat
Pawel Mierzejewski1, Artur Rogowski, Roman Stefanski
1Department of Pharmacology, Warsaw Medical Academy, Warsaw, Poland.
Aims:
The aim of the present study was to evaluate the relationship between operant oral ethanol self-administration and intravenous (i.v.) cocaine self-administration in male Wistar rats.
Methods:
Twenty-four rats were trained to lever press for 8% v/v ethanol in the sucrose-fading procedure. The subjects with the highest (high ethanol responders [HER], n = 7) and lowest (low ethanol responders [LER], n = 7) ethanol intakes were selected for further experiments. After a wash-out period, during which i.v. catheters were implanted, the HER and LER were trained to nose-poke for cocaine infusions (0.33 mg/kg/infusion, a FR1 schedule) for nine daily sessions.
Results:
The HER emitted more 'active' nose-pokes and obtained more cocaine infusions during sessions 2-4. Drug-seeking behaviour in the absence of cocaine reinforcement was then assessed for three consecutive extinction sessions. No between-group differences were found in terms of extinction of cocaine seeking. Locomotor responses to a novel environment were also similar in both groups.
Conclusions:
The present results suggest that a propensity to self-administer ethanol predicts more rapid acquisition of cocaine self-administration behaviour but does not influence subsequent behaviour during extinction.
