Effects of intraaccumbens injections of dopamine agonists and antagonists on sucrose and sucrose-ethanol reinforced responding
| Autor: | Herman H. Samson, Clyde W. Hodge, Miki Haraguchi, Gerald A. Tolliver |
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| Rok vydání: | 1994 |
| Předmět: |
Agonist
Male medicine.medical_specialty Sucrose Dextroamphetamine Quinpirole Microinjections medicine.drug_class Clinical Biochemistry Dopamine Agents Toxicology Biochemistry Nucleus Accumbens Behavioral Neuroscience chemistry.chemical_compound Dopamine Internal medicine Salicylamides medicine Animals Ergolines Biological Psychiatry Pharmacology Raclopride Ethanol Dose-Response Relationship Drug Antagonist Rats Dose–response relationship Dopamine D2 Receptor Antagonists Endocrinology chemistry Anesthesia Catecholamine Conditioning Operant Dopamine Antagonists Psychology Reinforcement Psychology medicine.drug |
| Zdroj: | Pharmacology, biochemistry, and behavior. 48(1) |
| ISSN: | 0091-3057 |
| Popis: | The present experiment tested the effects of intraaccumbens injections of dopamine (DA) agonists and antagonists on operant responding reinforced by sucrose and sucrose/ethanol solutions. The mixed DA agonist d-amphetamine (20.0 micrograms/microliters) significantly reduced responding reinforced by a low concentration sucrose solution (2% w/v) by 48% and 38% compared to no injection and sham control values, respectively. The addition of ethanol (10%) to a low concentration sucrose solution (3%) presented as the reinforcer changed the response pattern from a continuous moderate response rate, over a 30 min session, to an initial high response rate that terminated after approximately 10 min. With sucrose/ethanol reinforcement, d-amphetamine slowed the initial high response rate but extended responding throughout the 30 min sessions. However, no significant changes were observed in number of responses per session. When 75% sucrose (w/v) was presented as the reinforcer, d-amphetamine did not change the total number of responses/session, but response patterns were again altered from high initial rates with early offset to slow steady rates that continued for the duration of sessions. The D2 DA antagonist raclopride (0.1-5.0 micrograms/microliters) resulted in a dose-dependent decrease in responding reinforced by 75% sucrose. The baseline patterns, response totals, and effects of the DA antagonists resemble our previously reported findings with 10% ethanol (v/v) reinforcement. These data support the conclusion that mesolimbic DA activity may be a common mechanism in ethanol reinforced behavior and behavior reinforced by other substances, but suggest that the nature of behavioral change may depend upon the reinforcer. |
| Databáze: | OpenAIRE |
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