| Abstract No.: | A-C1082 |
| Country: | Canada |
| | |
| Title: | THE EFFECT OF ACUTE ETHANOL ON OPIOID PEPTIDE RELEASE IN THE NUCLEUS ACCUMBENS OF ALCOHOL-PREFERRING AA AND ALCOHOL-AVOIDING ANA RATS |
| | |
| Authors/Affiliations: | 1 Minh Lam*;
1 McGill University, Montreal, QC, Canada
|
| | |
| Content: | Objectives: The selectively bred lines of alcohol-preferring AA (Alko Alcohol) and alcohol-avoiding ANA (Alko Non-Alcohol) rats have been used experimentally to demonstrate differences in physiology and neurobiology, which could account for their difference in alcohol consumption. There is experimental evidence demonstrating that there are differences in distinct components of the endogenous opioid system in various brain regions between the AA and ANA lines of animals. Moreover, experiments have demonstrated that the AA and ANA animals show differences in the endogenous opioid system at the level of nucleus accumbens, a brain region involved in alcohol consumption and reinforcement. Thus, the goal of this current study was to investigate the hypothesis that the AA and ANA animals will show differences in the release of the opioid peptide β-endorphin at the level of the nucleus accumbens in response to acute systemic administration of various doses of ethanol.
Materials and Methods: In order to investigate this hypothesis, the technique of in vivo microdialysis was used. AA and ANA rats were unilaterally implanted with a guide cannula to aim microdialysis probes at the level of nucleus accumbens. Intraperitoneal (i.p.) injections of 0.0, 1.5, 2.0, 2.5g ethanol/kg body weight were administered to the rats. Dialysate samples were collected at 30- minute intervals at distinct time points prior to and following the i.p. injection. Radioimmunoassay specific for beta-endorphin was used to determine the effect of ethanol on the content of beta-endorphin in the dialysate.
Results: We report a sharp and transient increase in the release of beta-endorphin at the level of nucleus accumbens of AA but not of ANA rats in response to the 2.5g/kg dose of ethanol.
Conclusion: Therefore, the difference in the ethanol-stimulated β-endorphin release at the level of the nucleus accumbens between AA and ANA rats could explain, in a part, the differences in alcohol consumption between these two selectively bred lines of rats.
|
| | |
| Back |
|
