Opioid Receptors Regulate the Extinction of Pavlovian Fear Conditioning.
- 1 January 2003
- journal article
- research article
- Published by American Psychological Association (APA) in Behavioral Neuroscience
- Vol. 117 (6) , 1292-1301
- https://doi.org/10.1037/0735-7044.117.6.1292
Abstract
Rats received a single pairing of an auditory conditioned stimulus (CS) with a footshock unconditioned stimulus (US). The fear (freezing) that had accrued to the CS was then extinguished. Injection of naloxone prior to this extinction significantly impaired the development of extinction. This impairment was mediated by opioid receptors in the brain and was not observed when naloxone was injected after extinction training. Finally, an injection of naloxone on test failed to reinstate extinguished responding that had already accrued to the CS. These experiments show that opioid receptors regulate the development, but not the expression, of fear extinction and are discussed with reference to the roles of opioid receptors in US processing, memory, and appetitive motivation.Keywords
This publication has 34 references indexed in Scilit:
- Effects of D-cycloserine on extinction of conditioned freezing.Behavioral Neuroscience, 2003
- Isolation reduces contextual but not auditory-cue fear conditioning: A role for endogenous opioids.Behavioral Neuroscience, 1999
- Blocking of acquisition but not expression of conditioned fear-potentiated startle by NMDA antagonists in the amygdalaNature, 1990
- Separable roles of hippocampal granule cells in forgetting and pyramidal cells in remembering spatial informationBrain Research, 1987
- Pharmacological evidence of a central effect of naltrexone, morphine, and β-endorphin and a peripheral effect of met- and leu-enkephalin on retention of an inhibitory response in miceBehavioral and Neural Biology, 1985
- Naloxone attenuates amnesia caused by amygdaloid stimulation: The involvement of a central opioid systemBrain Research, 1983
- Naloxone reverses retrograde amnesia induced by electroconvulsive shockBehavioral and Neural Biology, 1982
- Effects of naloxone on pavlovian conditioning of eyeblink and heart rate responses in rabbitsLife Sciences, 1980
- A perceptual-defensive-recuperative model of fear and painBehavioral and Brain Sciences, 1980
- Naloxone and shock-elicited freezing in the rat.Journal of Comparative and Physiological Psychology, 1979