title: Chronic treatment with fluoxetine prevents the return of extinguished auditory-cued conditioned fear.
abstract: BACKGROUND
  We have recently shown that post-extinction exposure of rats to a sub-threshold reminder shock can reactivate extinguished context-related freezing and found that chronic treatment with fluoxetine before fear extinction prevents this phenomenon.
  
  
  OBJECTIVE
  In the present study, we examined whether these findings would be confirmed with auditory fear conditioning.
  
  
  METHODS
  Rats were initially submitted to a session of five tone-shock pairings with either a 0.7- or 0.1-mA shock and underwent, 3 days later, a session of 20 tone-alone trials.
  
  
  RESULTS
  At the beginning of this latter session, we observed cue-conditioned freezing in rats that received the strong, but not the weak, shock. At the end, both groups (strong and weak shocks) displayed similar low levels of freezing, indicating fear extinction in rats exposed to the strong shock. These rats exhibited again high levels of cue-evoked freezing when exposed to three tone-shock pairings with 0.1-mA shock. This reemergence of cue-conditioned fear was completely abolished by chronic (over a 21-day period) fluoxetine treatment which spared, when administered before the initial fear conditioning, the original tone-shock association.
  
  
  CONCLUSIONS
  These data extend our previous findings and suggest that chronic fluoxetine treatment favor extinction memory by dampening the reactivation of the original tone-shock association.
authors.affiliation: Laboratoire de Neurobiologie et Psychotraumatologie, Equipe d'Accueil 4321, Université de Nice-Sophia Antipolis, 06108 Nice, France. olivier.deschaux@unice.fr
authors.forename: Olivier
authors.initials: O
authors.lastname: Deschaux
authors.forename: Guillaume
authors.initials: G
authors.lastname: Spennato
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Moreau
authors.forename: René
authors.initials: R
authors.lastname: Garcia
mesh_terms: D000161:Acoustic Stimulation / Q000009:adverse effects; D000704:Analysis of Variance; D000818:Animals; D018687:Antidepressive Agents, Second-Generation / Q000494:pharmacology*; D001522:Behavior, Animal / Q000187:drug effects; D003214:Conditioning, Classical / Q000187:drug effects*; D003463:Cues; D005108:Extinction, Psychological / Q000187:drug effects*; D005239:Fear / Q000187:drug effects*; D005473:Fluoxetine / Q000494:pharmacology*; D046352:Freezing Reaction, Cataleptic / Q000187:drug effects; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D021641:Recognition, Psychology / Q000187:drug effects; D055502:Secondary Prevention; D013997:Time Factors
chemical_list: D018687:Antidepressive Agents, Second-Generation; D005473:Fluoxetine