Accumbalμ-Opioid Receptors Modulate Ethanol Intake in Alcohol-Preferring Alko Alcohol Rats
| Autor: | Ville Oinio, Mikko Airavaara, Petteri Piepponen, Atso Raasmaja, Pia Bäckström, Johanna Uhari-Väänänen, Kalervo Kiianmaa |
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| Rok vydání: | 2016 |
| Předmět: |
Male
Agonist endocrine system medicine.medical_specialty Alcohol Drinking Microinjections medicine.drug_class Receptors Opioid mu Medicine (miscellaneous) Nucleus accumbens Toxicology κ-opioid receptor Nucleus Accumbens 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Reward Species Specificity Opioid receptor Internal medicine mental disorders medicine Animals Opioid peptide reproductive and urinary physiology Opioidergic Dose-Response Relationship Drug Ethanol Morphine Chemistry Receptors Opioid kappa 3 4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide (trans)-Isomer Enkephalin Ala(2)-MePhe(4)-Gly(5) Rats 030227 psychiatry Psychiatry and Mental health DAMGO Endocrinology μ-opioid receptor Somatostatin 030217 neurology & neurosurgery |
| Zdroj: | Alcoholism: Clinical and Experimental Research. 40:2114-2123 |
| ISSN: | 0145-6008 |
| Popis: | Background The nucleus accumbens shell is a key brain area mediating the reinforcing effects of ethanol (EtOH). Previously, it has been shown that the density of μ-opioid receptors in the nucleus accumbens shell is higher in alcohol-preferring Alko Alcohol (AA) rats than in alcohol-avoiding Alko Non-Alcohol rats. In addition, EtOH releases opioid peptides in the nucleus accumbens and opioid receptor antagonists are able to modify EtOH intake, all suggesting an opioidergic mechanism in the control of EtOH consumption. As the exact mechanisms of opioidergic involvement remains to be elucidated, the aim of this study was to clarify the role of accumbal μ- and κ-opioid receptors in controlling EtOH intake in alcohol-preferring AA rats. Methods Microinfusions of the μ-opioid receptor antagonist CTOP (0.3 and 1 μg/site), μ-opioid receptor agonist DAMGO (0.03 and 0.1 μg/site), nonselective opioid receptor agonist morphine (30 μg/site), and κ-opioid receptor agonist U50488H (0.3 and 1 μg/site) were administered via bilateral guide cannulas into the nucleus accumbens shell of AA rats that voluntarily consumed 10% EtOH solution in an intermittent, time-restricted (90-minute) 2-bottle choice access paradigm. Results CTOP (1 μg/site) significantly increased EtOH intake. Conversely, DAMGO resulted in a decreasing trend in EtOH intake. Neither morphine nor U50488H had any effect on EtOH intake in the used paradigm. Conclusions The results provide further evidence for the role of accumbens shell μ-opioid receptors but not κ-opioid receptors in mediating reinforcing effects of EtOH and in regulating EtOH consumption. The results also provide support for views suggesting that the nucleus accumbens shell has a major role in mediating EtOH reward. |
| Databáze: | OpenAIRE |
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