title: Decreased accumbens dopamine release after cocaine challenge in behaviorally sensitized female rats.
abstract: The effects of the competitive NMDA receptor antagonist CPP on the initiation of behavioral sensitization to acute cocaine and basal and acute cocaine-induced dopamine (DA) release in the nucleus accumbens (NAC) were assessed in female Sprague-Dawley rats. Cocaine pretreated rats (30 mg/kg IP, once daily for 7 days) challenged with cocaine (10 mg/kg) on day 8 displayed increased motor activity relative to controls challenged with cocaine on day 8. This effect was blocked in rats receiving CPP (2 mg/kg) 15 min prior to all cocaine pretreatments. Basal DA levels in the NAC of both cocaine-pretreated and CPP plus cocaine-pretreated rats were higher on day 8 compared to controls. Acute cocaine challenge on day 8 resulted in increased extracellular DA concentrations in the NAC in control rats, no increase in rats pretreated with CPP plus cocaine, and a decrease in rats pretreated with cocaine only. These data demonstrate that development of behavioral sensitization to cocaine in female Sprague-Dawley rats can be completely blocked by a peripherally administered competitive NMDA receptor antagonist and that an increase in DA release in the NAC after a cocaine challenge is not an absolute requirement for expression of motor sensitization to cocaine in female rats.
authors.affiliation: Department of Physiology and Pharmacology, University of New England, College of Osteopathic Medicine, 11 Hills Beach Road, Biddeford, ME 04005, USA.
authors.forename: D W
authors.initials: DW
authors.lastname: Johnson
authors.forename: P
authors.initials: P
authors.lastname: Eodice
authors.forename: H
authors.initials: H
authors.lastname: Winterbottom
authors.forename: D J
authors.initials: DJ
authors.lastname: Mokler
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D003042:Cocaine / Q000494:pharmacology*; D004298:Dopamine / Q000378:metabolism*; D018765:Dopamine Uptake Inhibitors / Q000494:pharmacology*; D005260:Female; D017551:Microdialysis; D009043:Motor Activity / Q000187:drug effects; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism*; D010879:Piperazines / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
chemical_list: D018765:Dopamine Uptake Inhibitors; D010879:Piperazines; D015102:3,4-Dihydroxyphenylacetic Acid; C050592:3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid; D003042:Cocaine; D004298:Dopamine