Ethanol-induced conditioned place preference is expressed through a ventral tegmental area dependent mechanism.
The authors examined the role of the ventral tegmental area (VTA) and nucleus accumbens (NAc) in the expression of ethanol-induced conditioned place preference (CPP). After cannulas were implanted, male DBA/2J mice underwent an unbiased Pavlovian-conditioning procedure for ethanol-induced CPP. Before preference testing, the mice were injected intra-VTA (Experiments 1 and 3) or intra-NAc (Experiment 2) with the nonselective opioid antagonist methylnaloxonium (0-ng, 375-ng, or 750-ng total infusion; Experiments 1 and 2) or the gamma aminobutyric acid (GABA(B)) agonist baclofen (0-ng, 25-ng, or 50-ng total infusion; Experiment 3). Intra-VTA methylnaloxonium or baclofen decreased ethanol-induced CPP, whereas intra-NAc methylnaloxonium had no effect. These findings indicate that the conditioned rewarding effect of ethanol is expressed through a VTA-dependent mechanism that involves both opioid and GABA(B) receptors.
Bechtholt
Anita J
AJ
Department of Behavioral Neuroscience and Portland Alcohol Research Center, Oregon Health & Science University, Portland, OR 97239-3098, USA.
Cunningham
Christopher L
CL
D000818:Animals; D001418:Baclofen / Q000008:administration & dosage / Q000494:pharmacology; D002492:Central Nervous System Depressants / Q000494:pharmacology*; D003214:Conditioning, Classical; D000431:Ethanol / Q000494:pharmacology*; D018755:GABA Agonists / Q000008:administration & dosage / Q000494:pharmacology; D008297:Male; D051379:Mice; D009270:Naloxone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D000644:Quaternary Ammonium Compounds; D018080:Receptors, GABA-B / Q000502:physiology; D011957:Receptors, Opioid / Q000502:physiology; D012054:Reinforcement, Psychology; D013028:Space Perception; D017557:Ventral Tegmental Area / Q000187:drug effects* / Q000502:physiology*
D002492:Central Nervous System Depressants; D018755:GABA Agonists; D000644:Quaternary Ammonium Compounds; D018080:Receptors, GABA-B; D011957:Receptors, Opioid; D009270:Naloxone; D000431:Ethanol; C041269:N-methylnaloxone; D001418:Baclofen