Comparison of the stimulus properties of ethanol and the Ca2+ channel antagonist nimodipine in rats
| Autor: | A. Lohmann, R. Schneider, Jean De Vry, René De Beun |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Male
Pharmacology Stimulus (physiology) chemistry.chemical_compound Conditioning Psychological Avoidance Learning medicine Animals Rats Wistar Nimodipine ED50 Analysis of Variance Ethanol Behavior Animal Dose-Response Relationship Drug Chemistry Dihydropyridine Antagonist Central Nervous System Depressants Calcium Channel Blockers Rats Taste Taste aversion Conditioning medicine.drug |
| Zdroj: | European Journal of Pharmacology. 306:5-13 |
| ISSN: | 0014-2999 |
| Popis: | A variety of L-type Ca2+ channel antagonists, including the dihydropyridine derivative nimodipine, have been shown to be effective in reducing ethanol intake and preference in animal models of alcoholism. The behavioral mechanism involved in the anti-alcohol effects of nimodipine are, however, not clear yet. The aim of the present study was to investigate the possibility that the effects of nimodipine on ethanol intake are based on stimulus substitution. Therefore, rats were trained to discriminate ethanol (12.5% w/v, 1000 mg/kg i.p.) from saline in a two-lever food-reinforced drug discrimination procedure (dose range of ethanol tested: 125-1000 mg/kg i.p., ED50 value: 488 mg/kg). In cross-generalization tests with nimodipine (0.15-15 mg/kg i.p.), stimulus substitution was not noted. In addition, a cross-familiarization conditioned taste aversion paradigm was utilized. In rats, 1000 mg/kg i.p. ethanol was used as the reference drug producing a conditioned taste aversion. Effects of preexposure to ethanol (500-1500 mg/kg i.p.) and nimodipine (7.5-30 mg/kg i.p.) on the magnitude of the ethanol-induced conditioned taste aversion were investigated as an index for stimulus similarity between preexposure and reference drug. Preexposure to both ethanol and nimodipine prevented the development of a conditioned taste aversion. Contrary to the drug discrimination results, these latter findings suggest that there may be similarities between the stimulus properties of nimodipine and ethanol. Moreover, the apparent discrepancy between the results obtained in drug discrimination and cross-familiarization conditioned taste aversion suggests that different stimulus properties of ethanol control behavior in both procedures. The finding that, under particular conditions, ethanol and nimodipine appear to share common stimulus properties needs to be further evaluated, as this may be related to the reported anti-alcohol effects of nimodipine and other Ca2+ channel antagonists. |
| Databáze: | OpenAIRE |
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