title: Wistar rats acquire and maintain self-administration of 20 % ethanol without water deprivation, saccharin/sucrose fading, or extended access training.
abstract: BACKGROUND
  Operant self-administration (SA) is an important model of motivation to consume ethanol (EtOH), but low rates of voluntary consumption in rats are thought to necessitate water deprivation and saccharin/sucrose fading for acquisition of responding.
  
  
  OBJECTIVE
  Here, we sought to devise an effective model of SA that does not use water deprivation or saccharin/sucrose fading.
  
  
  METHODS
  First, we tested if Wistar rats would acquire and maintain SA behavior of 20 % EtOH under two conditions, water deprivation (WD) and non-water deprivation (NWD). Second, we tested the efficacy of our SA procedure by confirming a prior study which found that the NK1 antagonist L822429 specifically blocked stress-induced reinstatement of EtOH seeking but not SA. Finally, we assessed the effect of naltrexone, an FDA-approved medication for alcohol dependence that has been shown to suppress EtOH SA in rodents.
  
  
  RESULTS
  Lever presses (LPs) and rewards were consistent with previous reports that utilized WD and saccharin/sucrose fading. Similar to previous findings, we found that L822429 blocked stress-induced reinstatement but not baseline SA of 20 % EtOH. Moreover, naltrexone dose-dependently decreased alcohol intake and motivation to consume alcohol for rats that are self-administering 20 % EtOH.
  
  
  CONCLUSIONS
  Our findings provide a method for voluntary oral EtOH SA in rats that is convenient for experimenters and eliminates the potential confound of sweeteners in EtOH-operant SA studies. Unlike models that use intermittent access to 20 % EtOH, this method does not induce escalation, and based on pharmacological experiments, it appears to be driven by the positive reinforcing effects of EtOH.
authors.affiliation: Laboratory of Clinical and Translational Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, 20892, USA, eric.augier@nih.gov.
authors.forename: E
authors.initials: E
authors.lastname: Augier
authors.forename: M
authors.initials: M
authors.lastname: Flanigan
authors.forename: R S
authors.initials: RS
authors.lastname: Dulman
authors.forename: A
authors.initials: A
authors.lastname: Pincus
authors.forename: J R
authors.initials: JR
authors.lastname: Schank
authors.forename: K C
authors.initials: KC
authors.lastname: Rice
authors.forename: C
authors.initials: C
authors.lastname: Kejun
authors.forename: M
authors.initials: M
authors.lastname: Heilig
authors.forename: J D
authors.initials: JD
authors.lastname: Tapocik
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D003216:Conditioning, Operant / Q000187:drug effects*; D000431:Ethanol / Q000008:administration & dosage*; D008297:Male; D009042:Motivation / Q000187:drug effects; D009271:Naltrexone / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D012054:Reinforcement, Psychology; D012201:Reward; D012439:Saccharin / Q000008:administration & dosage*; D012646:Self Administration; D013395:Sucrose / Q000008:administration & dosage*; D014868:Water Deprivation
chemical_list: D000431:Ethanol; D013395:Sucrose; D009271:Naltrexone; D012439:Saccharin