Related Experiment Video
Updated: Jun 5, 2026

Extinction Training During the Reconsolidation Window Prevents Recovery of Fear
Published on: August 24, 2012
Kappa opioid receptors mediate where fear is expressed following extinction training
Sindy Cole1, Rick Richardson, Gavan P McNally
1School of Psychology, The University of New South Wales, Sydney 2052, Australia.
Abstract:
Six experiments used a within-subjects renewal design to examine the involvement of kappa opioid receptors (KORs) in regulating the expression and recovery of extinguished fear. Rats were trained to fear a tone conditioned stimulus (CS) via pairings with foot shock in a distinctive context (A). This was followed by extinction training of the CS in a second context (B). Finally, all rats were tested for fear to the tone in the extinction context (ABB) and the training (ABA) or a novel (ABC) context. Intracerebroventricular (ICV) infusion of the KOR antagonist nor-binaltorphimine dihydrochloride (nor-BNI) dose-dependently prevented ABA renewal of fear, but had no effect on the expression of ABC renewal, the expression of extinction, or the expression of nonextinguished fear. Conversely, pretest infusion of the KOR agonist U50,488 hydrochloride (U50,488) selectively facilitated the expression of ABA renewal and had no effect on the expression of extinction. Pretest infusion of nor-BNI had no effect on the expression of context-specific latent inhibition. Collectively, these results suggest that KORs gate the expression of fear following extinction training and may comprise a critical neuropeptide component of the circuitry underlying context-dependent expression of fear.
Related Concept Videos
Analgesia and Pain Management
Opioid Receptors: Overview
Role of Amygdala in Memory
One of the...
Principles of Classical Conditioning
During the...
Generalization, Discrimination, and Extinction
Generalization occurs when a behavior reinforced in one context is performed in similar situations. For instance, a student who studies diligently for calculus and receives excellent grades might apply the same study habits to psychology and history, expecting similar results. Generalization shows how learning in one setting can influence behavior in...
Functional Brain Systems: Limbic System
