title: Participation of the nociceptin/orphanin FQ receptor in ethanol-mediated locomotor activation and ethanol intake in preweanling rats.
abstract: Activation of nociceptin/orphanin FQ (NOP) receptors seems to attenuate ethanol-induced reinforcement in adult rodents. Since early ethanol exposure results in later increased responsiveness to ethanol, it is important to analyze NOP receptor modulation of ethanol-related behaviors during early ontogeny. By measuring NOP involvement in ethanol intake and ethanol-induced locomotor activation, we analyzed the specific participation of NOP receptors on these ethanol-related behaviors in two-week-old rats. In each experiment animals were pre-treated with the endogenous ligand for this receptor (nociceptin/orphanin FQ at 0.0, 0.5, 1.0 or 2.0 μg) or a selective NOP antagonist (J-113397 at 0.0, 0.5, 2.0 or 5.0 mg/kg). Results indicated that activation of the nociceptin receptor system had no effect on ethanol or water intake, while blockade of the NOP receptor has an unspecific effect on consummatory behavior: J-113397 increased ethanol (at a dose of 0.5 mg/kg) and water intake (at 0.5 and 5.0 mg/kg). Ethanol-mediated locomotor stimulation was attenuated by activation of the NOP system (nociceptin at 1.0 and 2.0 μg). Nociceptin had no effect on basal locomotor activity. Blockade of NOP receptors did not modify ethanol-induced locomotor activation. Contrary to what has been reported for adult rodents, nociceptin failed to suppress intake of ethanol in infants. Attenuation of ethanol-induced stimulation by activation of NOP receptor system suggests an early role of this receptor in this ethanol-related behavior.
authors: Department of Psychology, Center for Development and Behavioral Neuroscience, Binghamton University, Binghamton, NY 13902-6000, USA. rmiranda@binghamton.edu
authors: Roberto Sebastián
authors: RS
authors: Miranda-Morales
authors: Michael E
authors: ME
authors: Nizhnikov
authors: Dustin H
authors: DH
authors: Waters
authors: Norman E
authors: NE
authors: Spear
mesh_terms: D000428:Alcohol Drinking / Q000523:psychology*; D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D001562:Benzimidazoles / Q000494:pharmacology; D002492:Central Nervous System Depressants / Q000097:blood / Q000494:pharmacology*; D003259:Consummatory Behavior / Q000187:drug effects; D003345:Corticosterone / Q000097:blood; D003627:Data Interpretation, Statistical; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000097:blood / Q000494:pharmacology*; D005260:Female; D009043:Motor Activity / Q000187:drug effects*; D009292:Narcotic Antagonists; D018847:Opioid Peptides / Q000378:metabolism; D010880:Piperidines / Q000494:pharmacology; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D011957:Receptors, Opioid / Q000502:physiology*; D000094942:Nociceptin Receptor; D000097629:Nociceptin
chemical_list: D001562:Benzimidazoles; D002492:Central Nervous System Depressants; D003345:Corticosterone; D000431:Ethanol; D009292:Narcotic Antagonists; D018847:Opioid Peptides; D010880:Piperidines; D011957:Receptors, Opioid; D000094942:Nociceptin Receptor; D000097629:Nociceptin; C402921:J 113397; C000722285:Oprl1 protein, rat