Tags

Type your tag names separated by a space and hit enter

The effect of the mu-opioid receptor antagonist naloxone on extinction of conditioned fear in the developing rat.
Learn Mem. 2009 Mar; 16(3):161-6.LM

Abstract

Several recent studies report that neurotransmitters that are critically involved in extinction in adult rats are not important for extinction in young rats. Specifically, pretest injection of the gamma-aminobutryic acid (GABA) receptor inverse agonist FG7142 has no effect on extinction in postnatal day (P)17 rats, although it reverses extinction in P24 rats as reported by Kim and Richardson in an earlier paper. Further, pre-extinction injection of the N-methyl-d-aspartate (NMDA) receptor antagonist MK-801 has no effect on extinction in P17 rats, whereas it impairs long-term extinction in P24 rats as per Langton and colleagues in an earlier work. These findings indicate that extinction in P17 rats is qualitatively different from extinction in older rats. The present study examines the involvement of the endogenous opioid system in extinction in the developing rat using systemic injections of the mu-opioid receptor antagonist naloxone. Experiment 1 showed that injection of naloxone before extinction training disrupted the acquisition of extinction in both P17 and P24 rats. This effect was dependent on central rather than peripheral mu-opioid receptors (Experiment 2), and neither pre-test nor post-extinction injection of naloxone had effects on extinction (Experiments 3 and 4). Taken together, these findings indicate that opioid neurotransmission, in contrast to GABA and NMDA activity, is critical for extinction acquisition across development.

Authors+Show Affiliations

School of Psychology, University of New South Wales, Sydney 2052, Australia. jkim@psy.unsw.edu.auNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

19223599

Citation

Kim, Jee Hyun, and Rick Richardson. "The Effect of the Mu-opioid Receptor Antagonist Naloxone On Extinction of Conditioned Fear in the Developing Rat." Learning & Memory (Cold Spring Harbor, N.Y.), vol. 16, no. 3, 2009, pp. 161-6.
Kim JH, Richardson R. The effect of the mu-opioid receptor antagonist naloxone on extinction of conditioned fear in the developing rat. Learn Mem. 2009;16(3):161-6.
Kim, J. H., & Richardson, R. (2009). The effect of the mu-opioid receptor antagonist naloxone on extinction of conditioned fear in the developing rat. Learning & Memory (Cold Spring Harbor, N.Y.), 16(3), 161-6. https://doi.org/10.1101/lm.1282309
Kim JH, Richardson R. The Effect of the Mu-opioid Receptor Antagonist Naloxone On Extinction of Conditioned Fear in the Developing Rat. Learn Mem. 2009;16(3):161-6. PubMed PMID: 19223599.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - The effect of the mu-opioid receptor antagonist naloxone on extinction of conditioned fear in the developing rat. AU - Kim,Jee Hyun, AU - Richardson,Rick, Y1 - 2009/02/17/ PY - 2009/2/19/entrez PY - 2009/2/19/pubmed PY - 2009/5/2/medline SP - 161 EP - 6 JF - Learning & memory (Cold Spring Harbor, N.Y.) JO - Learn Mem VL - 16 IS - 3 N2 - Several recent studies report that neurotransmitters that are critically involved in extinction in adult rats are not important for extinction in young rats. Specifically, pretest injection of the gamma-aminobutryic acid (GABA) receptor inverse agonist FG7142 has no effect on extinction in postnatal day (P)17 rats, although it reverses extinction in P24 rats as reported by Kim and Richardson in an earlier paper. Further, pre-extinction injection of the N-methyl-d-aspartate (NMDA) receptor antagonist MK-801 has no effect on extinction in P17 rats, whereas it impairs long-term extinction in P24 rats as per Langton and colleagues in an earlier work. These findings indicate that extinction in P17 rats is qualitatively different from extinction in older rats. The present study examines the involvement of the endogenous opioid system in extinction in the developing rat using systemic injections of the mu-opioid receptor antagonist naloxone. Experiment 1 showed that injection of naloxone before extinction training disrupted the acquisition of extinction in both P17 and P24 rats. This effect was dependent on central rather than peripheral mu-opioid receptors (Experiment 2), and neither pre-test nor post-extinction injection of naloxone had effects on extinction (Experiments 3 and 4). Taken together, these findings indicate that opioid neurotransmission, in contrast to GABA and NMDA activity, is critical for extinction acquisition across development. SN - 1549-5485 UR - https://www.unboundmedicine.com/medline/citation/19223599/The_effect_of_the_mu_opioid_receptor_antagonist_naloxone_on_extinction_of_conditioned_fear_in_the_developing_rat_ L2 - https://medlineplus.gov/olderadulthealth.html DB - PRIME DP - Unbound Medicine ER -