title: Effects of cocaine combined with a social cue on conditioned place preference and nucleus accumbens monoamines after isolation rearing in rats.
abstract: BACKGROUND
  Social interaction during drug exposure can potentiate cocaine reward. Isolation rearing (ISO) during adolescence increases social interaction and may amplify this potentiation.
  
  
  OBJECTIVE
  The objectives of this study are to determine whether ISO alters conditioned place preference (CPP) for cocaine when combined with a social cue and to determine whether ISO alters the effects of cocaine when combined with social cue on nucleus accumbens shell (NAcS) dopamine (DA) and serotonin (5-HT).
  
  
  METHODS
  Male and female rats were either ISO or group (GRP) reared for 4 weeks during adolescence. CPP was performed using a low dose of cocaine (2 mg/kg or saline) with or without exposure to a novel same-sex conspecific during conditioning. In vivo microdialysis was performed using the same parameters.
  
  
  RESULTS
  ISO rats engaged in more social and aggressive behaviors during conditioning relative to GRP. Cocaine reduced social and aggressive behaviors in all rats. CPP was not influenced by rearing condition. Cocaine produced significant CPP, and a social cue produced CPP only in males. In contrast, the interaction of cocaine and a social cue on NAcS DA and 5-HT differed depending upon rearing condition. In isolates, cocaine-induced DA was attenuated, while cocaine plus a social cue produced potentiated DA and 5-HT.
  
  
  CONCLUSIONS
  Exposure to a low dose of cocaine in the presence of a social cue produced additive effects on CPP while producing synergistic effects on DA and 5-HT in the NAcS of ISO rats. The aversive effects of this compound stimulus may negate the rewarding effects in isolates.
authors.affiliation: Department of Psychology, University of Colorado Denver, North Classroom Building, Rm. 5002 1200 Larimer Street, Denver, CO, 80217-3364, USA.
authors.forename: Susan K
authors.initials: SK
authors.lastname: Grotewold
authors.forename: Vanessa L
authors.initials: VL
authors.lastname: Wall
authors.forename: Dayton J
authors.initials: DJ
authors.lastname: Goodell
authors.forename: Cassandra
authors.initials: C
authors.lastname: Hayter
authors.forename: Sondra T
authors.initials: ST
authors.lastname: Bland
mesh_terms: D000374:Aggression / Q000187:drug effects / Q000502:physiology; D000818:Animals; D003042:Cocaine / Q000494:pharmacology*; D003213:Conditioning, Psychological / Q000187:drug effects* / Q000502:physiology; D003463:Cues; D004298:Dopamine / Q000378:metabolism; D018765:Dopamine Uptake Inhibitors / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005106:Exploratory Behavior / Q000187:drug effects / Q000502:physiology; D005260:Female; D008297:Male; D017551:Microdialysis; D009714:Nucleus Accumbens / Q000187:drug effects* / Q000503:physiopathology; D011581:Psychological Tests; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000378:metabolism; D012727:Sex Characteristics; D012919:Social Behavior; D012934:Social Isolation; D012938:Social Perception; D013028:Space Perception / Q000187:drug effects / Q000502:physiology
chemical_list: D018765:Dopamine Uptake Inhibitors; D012701:Serotonin; D003042:Cocaine; D004298:Dopamine