Naloxone and baclofen attenuate ethanol's locomotor-activating effects in preweanling Sprague-Dawley rats.
Heterogeneous rat strains appear to be particularly sensitive to the sedative effects of ethanol as adults and insensitive to ethanol's stimulant effects. Recently, the authors found that ethanol induces stimulant effects in preweanling Sprague-Dawley rats. In adult mice, these effects seem to be governed by the mesocorticolimbic dopaminergic pathway, which can be modulated by means of GABA B agonist (baclofen) or opioid antagonist (naloxone) treatments. This study tested whether these pharmacological treatments might reduce the activating effect of ethanol in preweanling Sprague-Dawley rats. Twelve-day-old pups given naloxone (Experiment 1A) or baclofen (Experiment 1B) before ethanol administration were tested in terms of locomotor activity in a novel environment. Naloxone and baclofen significantly reduced the stimulating effect of ethanol but had no effect on locomotor activity patterns in water-treated controls. Blood ethanol levels were not affected by naloxone or baclofen (Experiment 2). During the preweanling period, opioid and GABA B receptors seem to be involved in the stimulating effect of ethanol.
Arias
Carlos
C
Center for Development and Behavioral Neuroscience, Binghamton University, Binghamton, NY 13902-6000, USA. afelicidade@yahoo.es
Mlewski
Estela C
EC
Molina
Juan Carlos
JC
Spear
Norman E
NE
D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D001418:Baclofen / Q000494:pharmacology*; D002492:Central Nervous System Depressants / Q000097:blood / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000097:blood / Q000494:pharmacology*; D018755:GABA Agonists / Q000494:pharmacology*; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D009270:Naloxone / Q000494:pharmacology*; D009292:Narcotic Antagonists / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D002492:Central Nervous System Depressants; D018755:GABA Agonists; D009292:Narcotic Antagonists; D009270:Naloxone; D000431:Ethanol; D001418:Baclofen