Acute withdrawal from repeated cocaine treatment enhances latent inhibition of a conditioned fear response

C. A. Murphy, C. Heidbreder, J. Feldon

Research output: Contribution to journalArticlepeer-review

Abstract

Psychostimulant-induced locomotor sensitization and disrupted latent inhibition (LI) of a classically conditioned association are two paradigms that have been widely studied as animal behavioural models of psychosis. In this study we assessed the effects of withdrawal from the repeated intermittent administration of cocaine on LI of a conditioned fear response. Animals which were either preexposed (PE) to a tone conditioned stimulus (CS) or naive to the tone (i.e. non-preexposed: NPE) subsequently experienced 10 pairings of the tone CS with footshock. Afterwards, both groups received five daily injections of cocaine (20 mg/kg, i.p.) or saline. After 3 days of withdrawal from drug treatment, animals were tested for conditioned freezing to the context of the footshock chamber, and 1 day later, for conditioned freezing to the tone CS. Cocaine-sensitized animals exhibited markedly enhanced LI compared to saline-treated animals, due to the fact that NPE-cocaine animals spent more time freezing during the tone CS than NPE-saline animals, whereas PE-cocaine animals showed a tendency toward reduced freezing compared to the saline groups. While these results suggest the presence of increased anxiety in cocaine-withdrawn NPE animals, the absence of this effect in cocaine-withdrawn PE rats indicates that cocaine withdrawal also influences the retrieval of previously learned information.

Original languageEnglish
Pages (from-to)13-23
Number of pages11
JournalBehavioural Pharmacology
Volume12
Issue number1
DOIs
StatePublished - 2001
Externally publishedYes

Keywords

  • Aversive conditioning
  • Cocaine
  • Latent inhibition
  • Rat
  • Schizophrenia
  • Sensitization
  • Withdrawal

Fingerprint

Dive into the research topics of 'Acute withdrawal from repeated cocaine treatment enhances latent inhibition of a conditioned fear response'. Together they form a unique fingerprint.

Cite this