title: Cue-induced reinstatement of cocaine seeking in the rat "conflict model": effect of prolonged home-cage confinement.
abstract: OBJECTIVE
  Drug addiction is not just the repeated administration of drugs, but compulsive drug use maintained despite the accumulation of adverse consequences for the user. In an attempt to introduce adverse consequences of drug seeking to laboratory animals, we have developed the "conflict model," in which the access of rats to a reinforcing lever allowing self-administration requires passing of an electrified grid floor. In this model, the current intensity leading to complete abstinence from drug seeking can be measured individually. The present study was designed to evaluated whether reinstatement of drug or natural reward seeking, despite the presence of the electrical barrier, can be achieved by presentation of discrete cues that were associated with the reward, and whether prolonged home-cage confinement can facilitate such reinstatement in this model.
  
  
  METHODS
  The "conflict model" was used to test cue-induced reinstatement in the presence of the electrical barrier, after 1 or 14 days of home-cage confinement, in groups of rats that were previously trained to self-administer cocaine or sucrose.
  
  
  RESULTS
  Although similar shock intensity was required to suppress sucrose or cocaine self-administration, subjects exhibited significantly lower response to sucrose-associated as compared to cocaine-associated cues, during the reinstatement test. Importantly, cue-induced reinstatement of cocaine seeking was attenuated following 14 days of home-cage confinement.
  
  
  CONCLUSIONS
  The incorporation of aversive consequence in the self-administration model enable detection of what can be interpreted as a compulsive component unique to drug reinforcers. Moreover, the effect of the aversive consequence seems to increase following home-cage confinement.
authors.affiliation: Weizmann Institute of Science, 76100 Rehovot, Israel.
authors.forename: Noam
authors.initials: N
authors.lastname: Barnea-Ygael
authors.forename: Gal
authors.initials: G
authors.lastname: Yadid
authors.forename: Rami
authors.initials: R
authors.lastname: Yaka
authors.forename: Osnat
authors.initials: O
authors.lastname: Ben-Shahar
authors.forename: Abraham
authors.initials: A
authors.lastname: Zangen
mesh_terms: D000818:Animals; D016739:Behavior, Addictive / Q000523:psychology*; D003042:Cocaine / Q000008:administration & dosage*; D003216:Conditioning, Operant / Q000187:drug effects; D003220:Conflict, Psychological; D003463:Cues; D006799:Housing, Animal; D008297:Male; D023421:Models, Animal; D051381:Rats; D017207:Rats, Sprague-Dawley; D012646:Self Administration; D013997:Time Factors
chemical_list: D003042:Cocaine