title: Effects of SKF-83566 and haloperidol on performance on progressive ratio schedules maintained by sucrose and corn oil reinforcement: quantitative analysis using a new model derived from the Mathematical Principles of Reinforcement (MPR).
abstract: BACKGROUND
  Mathematical models can assist the interpretation of the effects of interventions on schedule-controlled behaviour and help to differentiate between processes that may be confounded in traditional performance measures such as response rate and the breakpoint in progressive ratio (PR) schedules.
  
  
  OBJECTIVE
  The effects of a D1-like dopamine receptor antagonist, 8-bromo-2,3,4,5-tetrahydro-3-methyl-5-phenyl-1H-3-benzazepin-7-ol hydrobromide (SKF-83566), and a D2-like receptor antagonist, haloperidol, on rats' performance on PR schedules maintained by sucrose and corn oil reinforcers were assessed using a new model derived from Killeen's (Behav Brain Sci 17:105-172, 1994) Mathematical Principles of Reinforcement.
  
  
  METHODS
  Separate groups of rats were trained under a PR schedule using sucrose or corn oil reinforcers. SKF-83566 (0.015 and 0.03 mg kg(-1)) and haloperidol (0.05 and 0.1 mg kg(-1)) were administered intraperitoneally (five administrations of each treatment). Running and overall response rates in successive ratios were analysed using the new model, and estimates of the model's parameters were compared between treatments.
  
  
  RESULTS
  Haloperidol reduced a (the parameter expressing incentive value) in the case of both reinforcers, but did not affect the parameters related to response time and post-reinforcement pausing. SKF-83566 reduced a and k (the parameter expressing sensitivity of post-reinforcement pausing to the prior inter-reinforcement interval) in the case of sucrose, but did not affect any of the parameters in the case of corn oil.
  
  
  CONCLUSIONS
  The results are consistent with the hypothesis that blockade of both D1-like and D2-like receptors reduces the incentive value of sucrose, whereas the incentive value of corn oil is more sensitive to blockade of D2-like than D1-like receptors.
authors.affiliation: Psychopharmacology Section, Division of Psychiatry, University of Nottingham, Room B109, Medical School, Queen's Medical Centre, Nottingham, NG7 2UH, UK, olarte-sanchez@cardiff.ac.uk.
authors.forename: C M
authors.initials: CM
authors.lastname: Olarte-Sánchez
authors.forename: L
authors.initials: L
authors.lastname: Valencia-Torres
authors.forename: H J
authors.initials: HJ
authors.lastname: Cassaday
authors.forename: C M
authors.initials: CM
authors.lastname: Bradshaw
authors.forename: E
authors.initials: E
authors.lastname: Szabadi
mesh_terms: D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D003216:Conditioning, Operant / Q000187:drug effects; D003314:Corn Oil / Q000008:administration & dosage; D018492:Dopamine Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D065127:Dopamine D2 Receptor Antagonists; D004305:Dose-Response Relationship, Drug; D005260:Female; D006220:Haloperidol / Q000008:administration & dosage / Q000494:pharmacology*; D007274:Injections, Intraperitoneal; D008962:Models, Theoretical; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time / Q000187:drug effects; D017447:Receptors, Dopamine D1 / Q000037:antagonists & inhibitors; D012055:Reinforcement Schedule; D013395:Sucrose / Q000008:administration & dosage
chemical_list: D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D003314:Corn Oil; D018492:Dopamine Antagonists; D065127:Dopamine D2 Receptor Antagonists; D006220:Haloperidol; D017447:Receptors, Dopamine D1; D013395:Sucrose; C044846:SKF83566