Ethanol enhances the release of dopamine and serotonin in the nucleus accumbens of HAD and LAD lines of rats.
The effects of intraperitoneal administration of ethanol, 0.5, 1.0, and 2.0 g/kg body weight, on the extracellular concentrations of dopamine (DA), serotonin (5-HT), and their major metabolites were studied in the nucleus accumbens (ACC) of alcohol-naive, selectively bred high-alcohol-drinking (HAD) and low-alcohol-drinking (LAD) lines of rats using the technique of microdialysis. In both lines, the extracellular levels of DA were increased following the injection of 1.0 and 2.0 g of ethanol/kg body weight while only the 2.0-g/kg dose elevated the concentration of 5-HT. None of the ethanol doses altered the extracellular levels of the major metabolites of DA and 5-HT. Dose-response curves for DA and 5-HT release indicated no marked difference in the sensitivity to ethanol between the lines. Local perfusion with 60 mM K+ through the microdialysis probe markedly enhanced the release of DA and 5-HT in the ACC of both lines; there was a small difference between the lines in the amounts of DA, but not 5-HT, released by K(+)-stimulation. Overall, the results indicate that (1) the ACC DA system is more sensitive than the ACC 5-HT system to intraperitoneal ethanol administration in both lines and (2) there is no evidence for a relationship between alcohol preference and sensitivity of the ACC DA and 5-HT systems to acute intraperitoneal ethanol administration.
Yoshimoto
K
K
Department of Psychiatry, Indiana University School of Medicine, Indianapolis.
McBride
W J
WJ
Lumeng
L
L
Li
T K
TK
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000437:Alcoholism / Q000503:physiopathology*; D000818:Animals; D004298:Dopamine / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000494:pharmacology*; D006719:Homovanillic Acid / Q000378:metabolism; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D007274:Injections, Intraperitoneal; D008297:Male; D009714:Nucleus Accumbens / Q000187:drug effects* / Q000503:physiopathology; D011188:Potassium / Q000493:pharmacokinetics; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism*
D015102:3,4-Dihydroxyphenylacetic Acid; D012701:Serotonin; D000431:Ethanol; D006897:Hydroxyindoleacetic Acid; D011188:Potassium; D004298:Dopamine; D006719:Homovanillic Acid