title: Role of ethanol-derived acetaldehyde in operant oral self-administration of ethanol in rats.
abstract: BACKGROUND
  The role of ethanol-derived acetaldehyde has not been examined yet on performance in a model of operant oral self-administration. However, previous studies reported that an acetaldehyde-sequestering agent, D-penicillamine (DP) and an inhibitor of catalase-mediated acetaldehyde production, 3-amino-1,2,4-triazole (3-AT) reduce voluntary ethanol consumption.
  
  
  OBJECTIVE
  The aim of our investigation was to evaluate the effects of DP and 3-AT on acquisition and maintenance of oral operant ethanol self-administration.
  
  
  METHODS
  Using operant chambers, rats learned to nose poke in order to receive ethanol solution (5-10 % v/v) under an FR1 schedule of reinforcement in which discrete light and tone cues were presented during ethanol delivery.
  
  
  RESULTS
  DP and 3-AT impair the acquisition of ethanol self-administration, whereas its maintenance is not affected neither by drug given alone for both 10 or 5 % ethanol nor by drugs association for 5 % ethanol. Moreover, when the concentration of ethanol was diminished from 10 to 5 %, rats increased the rate of self-administration behaviour.
  
  
  CONCLUSIONS
  These findings suggest that brain acetaldehyde plays a critical role during acquisition of operant self-administration in ethanol-naïve rats. In contrast, during the maintenance phase, acetaldehyde could contribute to ethanol self-administration by a combined mechanism: On one hand, its lack (by DP or 3-AT) might result in further ethanol-seeking and taking and, on the other, inhibition of ethanol metabolism (by 3-AT) might release an action of the un-metabolised fraction of ethanol that does not overall result in compromising maintenance of ethanol self-administration.
authors: Department of Chemistry and Pharmacy, University of Sassari, Via Muroni, 23, 07100, Sassari, Italy. apeana@uniss.it.
authors: Alessandra T
authors: AT
authors: Peana
authors: Department of Chemistry and Pharmacy, University of Sassari, Via Muroni, 23, 07100, Sassari, Italy.
authors: Valeria
authors: V
authors: Porcheddu
authors: Department of Chemistry and Pharmacy, University of Sassari, Via Muroni, 23, 07100, Sassari, Italy.
authors: Federico
authors: F
authors: Bennardini
authors: Department of Chemistry and Pharmacy, University of Sassari, Via Muroni, 23, 07100, Sassari, Italy.
authors: Antonio
authors: A
authors: Carta
authors: Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy.
authors: Michela
authors: M
authors: Rosas
authors: Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy.|Centre of Excellence on Neurobiology of Addiction, University of Cagliari, Cagliari, Italy.
authors: Elio
authors: E
authors: Acquas
mesh_terms: D000079:Acetaldehyde / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000284:Administration, Oral; D000428:Alcohol Drinking / Q000378:metabolism* / Q000523:psychology; D000640:Amitrole / Q000494:pharmacology; D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects* / Q000502:physiology*; D003463:Cues; D000431:Ethanol / Q000008:administration & dosage*; D008297:Male; D010396:Penicillamine / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D012054:Reinforcement, Psychology; D012646:Self Administration
chemical_list: D000431:Ethanol; D010396:Penicillamine; D000079:Acetaldehyde; D000640:Amitrole
keywords: 3-Amino-1,2,4-triazole; Acetaldehyde; D-Penicillamine; Ethanol; Oral operant self-administration; Wistar rats