Projects per year
Abstract
BackgroundThe nucleus accumbens shell is a key brain area mediating the reinforcing effects of ethanol (EtOH). Previously, it has been shown that the density of -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 - and -opioid receptors in controlling EtOH intake in alcohol-preferring AA rats.
MethodsMicroinfusions of the -opioid receptor antagonist CTOP (0.3 and 1g/site), -opioid receptor agonist DAMGO (0.03 and 0.1g/site), nonselective opioid receptor agonist morphine (30g/site), and -opioid receptor agonist U50488H (0.3 and 1g/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.
ResultsCTOP (1g/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.
ConclusionsThe results provide further evidence for the role of accumbens shell -opioid receptors but not -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.
MethodsMicroinfusions of the -opioid receptor antagonist CTOP (0.3 and 1g/site), -opioid receptor agonist DAMGO (0.03 and 0.1g/site), nonselective opioid receptor agonist morphine (30g/site), and -opioid receptor agonist U50488H (0.3 and 1g/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.
ResultsCTOP (1g/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.
ConclusionsThe results provide further evidence for the role of accumbens shell -opioid receptors but not -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.
| Original language | English |
|---|---|
| Journal | Alcoholism: Clinical and Experimental Research |
| Volume | 40 |
| Issue number | 10 |
| Pages (from-to) | 2114-2123 |
| Number of pages | 10 |
| ISSN | 0145-6008 |
| DOIs | |
| Publication status | Published - Oct 2016 |
| MoE publication type | A1 Journal article-refereed |
Fields of Science
- 317 Pharmacy
- Nucleus Accumbens Shell
- mu-Opioid Receptor
- kappa-Opioid Receptor
- Ethanol Intake
- Alko Alcohol Rat
- AVOIDING ANA RATS
- NUCLEUS-ACCUMBENS
- VENTRAL PALLIDUM
- MICRODIALYSIS PROFILE
- AGONIST U50,488H
- WISTAR RATS
- DRINKING
- REWARD
- AA
- RELEASE
Projects
- 1 Finished
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The role of opioid receptors in the development of alcohol addiction - Effect of increased and decreased expression on alcohol consumption in Alko Alcohol rats
Raasmaja, A. & Piepponen, T. P.
03/01/2011 → 31/12/2011
Project: Research project