title: Comparison of the conditioned reinforcing properties of a safety signal and appetitive stimulus: effects of d-amphetamine and anxiolytics.
abstract: BACKGROUND
  Safety signals providing relief are hypothesised to possess conditioned reinforcing properties, supporting the acquisition of a new response (AnR) as seen with appetitive stimuli. Such responding should also be sensitive to the rate-increasing effects of d-amphetamine and to the anxiolytics 8-OH-DPAT and diazepam.
  
  
  OBJECTIVE
  This study tests whether safety signals have conditioned reinforcing properties similar to those of stimuli-predicting reward.
  
  
  METHODS
  Rats received Pavlovian conditioning with either appetitive stimuli (CS+) or safety signals (conditioned inhibitors, CIs) plus truly random control (TRC) stimuli. The appetitive group received a CS + paired with a sucrose pellet and the safety signal group, a stimulus paired with shock omission. Stimuli were tested using an AnR procedure and following systemic d-amphetamine, the 5HT-1A agonist 8-OH-DPAT and the benzodiazepine diazepam in a counterbalanced design.
  
  
  RESULTS
  Effective conditioning selectively reduced contextual freezing during CI presentation in the safety signal group and increased food magazine responses (with respect to context and TRC) during CS + presentation in the appetitive group. The appetitive stimulus strongly supported AnR but the safety signal did not. Systemic d-amphetamine significantly potentiated lever pressing in the appetitive group but for the safety signal group, it either reduced it or had no effect, dependent on food deprivation state. 8-OH-DPAT and diazepam had no effect on responding in either group.
  
  
  CONCLUSIONS
  The safety signal did not support AnR and, therefore, did not exhibit conditioned reinforcing properties. Furthermore, d-amphetamine decreased responding when the safety signal was presented as a consequence, whilst increasing responding with appetitive-conditioned reinforcement. These results are discussed in terms of implications for opponent motivational theory.
authors.affiliation: Department of Psychology, University of Cambridge, Downing St., Cambridge, CB2 3EB, UK. af418@cam.ac.uk
authors.forename: A B P
authors.initials: AB
authors.lastname: Fernando
authors.forename: G P
authors.initials: GP
authors.lastname: Urcelay
authors.forename: A C
authors.initials: AC
authors.lastname: Mar
authors.forename: A
authors.initials: A
authors.lastname: Dickinson
authors.forename: T W
authors.initials: TW
authors.lastname: Robbins
mesh_terms: D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology*; D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology; D003214:Conditioning, Classical / Q000187:drug effects*; D003216:Conditioning, Operant / Q000187:drug effects; D003913:Dextroamphetamine / Q000494:pharmacology*; D003975:Diazepam / Q000494:pharmacology*; D005502:Food; D005508:Food Deprivation; D008297:Male; D051381:Rats; D012055:Reinforcement Schedule; D012201:Reward; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D013395:Sucrose / Q000008:administration & dosage
chemical_list: D014151:Anti-Anxiety Agents; D017366:Serotonin Receptor Agonists; D013395:Sucrose; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D003975:Diazepam; D003913:Dextroamphetamine