Baclofen alters ethanol-stimulated activity but not conditioned place preference or taste aversion in mice.
The present experiments examined the effects of the GABA(B) receptor agonist, baclofen, on the acquisition of ethanol-induced conditioned place preference (CPP) and conditioned taste aversion (CTA) in male DBA/2J mice. Mice in the CPP experiment received four pairings of ethanol (2g/kg) with a distinctive floor stimulus for a 5-min conditioning session (CS+ sessions). On intervening days (CS- sessions), mice received saline injections paired with a different floor type. On CS+ days, mice also received one of four doses of baclofen (0.0. 2.5, 5.0, or 7.5 mg/kg) 15 min before an injection of ethanol. For the preference test, all mice received saline injections, and were placed on a half-grid and half-hole floor for a 60-min session. Baclofen dose dependently reduced ethanol-stimulated activity, but did not alter the magnitude of ethanol-induced CPP at any dose. For the CTA experiment, mice were adapted to a 2-h per day water restriction regimen followed by five conditioning trials every 48 h. During conditioning trials, subjects received an injection of saline or baclofen (2.0 and 6.0 mg/kg) 15 min before injection of 2 g/kg ethanol or saline following 1-h access to a saccharin solution. Baclofen did not alter the magnitude of ethanol-induced CTA at any dose. In addition, baclofen alone did not produce a CTA. Overall, these studies show that activation of GABA(B) receptors with baclofen reduces ethanol-induced locomotor activation, but does not alter ethanol's rewarding or aversive effects in the CPP and CTA paradigms in DBA/2J mice.
Chester
J A
JA
Department of Behavioral Neuroscience, and Portland Alcohol Research Center, Oregon Health Sciences University, 97201-3098, USA.
Cunningham
C L
CL
D000818:Animals; D001418:Baclofen / Q000494:pharmacology*; D003213:Conditioning, Psychological / Q000187:drug effects* / Q000502:physiology; D000431:Ethanol / Q000494:pharmacology*; D018755:GABA Agonists / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008811:Mice, Inbred DBA; D009042:Motivation; D009043:Motor Activity / Q000187:drug effects* / Q000502:physiology; D018080:Receptors, GABA-B / Q000502:physiology; D012201:Reward; D013649:Taste / Q000187:drug effects / Q000502:physiology
D018755:GABA Agonists; D018080:Receptors, GABA-B; D000431:Ethanol; D001418:Baclofen