title: Greater avoidance of a heroin-paired taste cue is associated with greater escalation of heroin self-administration in rats.
abstract: Heroin addiction is a disease of chronic relapse affecting over half of its users. Therefore, modeling individual differences in addiction-like behavior is needed to better reflect the human condition. In a rodent model, avoidance of a cocaine-paired saccharin cue is associated with greater cocaine seeking and taking. Here, we tested whether rats would avoid a saccharin cue when paired with the opportunity to self-administer heroin and whether the rats that most greatly avoid the heroin-paired taste cue would exhibit the greatest drug escalation over time, the greatest willingness to work for drug, and the greatest heroin-induced relapse. Adult male Sprague-Dawley rats received 5 min access to a 0.15% saccharin solution followed by the opportunity to self-administer either saline or heroin for 3 hr (short access) or 6 hr (extended access). Following 16 to 18 pairings, terminal saccharin intake was used to categorize the rats into small (>200 licks/5min) or large (<200 licks/5min) suppressors and responding for drug was examined accordingly. Only 5% of the short access rats reached the criteria for large suppressors. This large suppressor did not differ from the small suppressors in drug-taking behavior. On the other hand, 50% of the extended access saccharin-heroin rats were large suppressors and showed the largest escalation of drug intake, drug-loading behavior, and the greatest relapse-like behaviors. Extended access small suppressors displayed drug-taking behaviors that were similar to rats in the short access heroin condition. Avoidance of a heroin-paired taste cue reliably identifies individual differences in addiction-like behavior for heroin using extended drug access.
authors.affiliation: Pennsylvania State University College of Medicine.
authors.forename: Caesar G
authors.initials: CG
authors.lastname: Imperio
authors.affiliation: Pennsylvania State University College of Medicine.
authors.forename: Patricia S
authors.initials: PS
authors.lastname: Grigson
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D003463:Cues; D003932:Heroin / Q000008:administration & dosage*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012439:Saccharin / Q000008:administration & dosage; D012646:Self Administration; D013649:Taste
chemical_list: D003932:Heroin; D012439:Saccharin