S-3,4-DCPG, a potent orthosteric agonist for the mGlu8 receptor, facilitates extinction and inhibits the reinstatement of morphine-induced conditioned place preference in male rats.

Autor: Kahvandi N; Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran; Department of Physiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran., Ebrahimi Z; Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran; Department of Physiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran., Sharifi M; Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran., Karimi SA; Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran; Department of Neuroscience, School of Sciences and Advanced Technology in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran., Shahidi S; Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran; Department of Neuroscience, School of Sciences and Advanced Technology in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran., Salehi I; Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran; Department of Neuroscience, School of Sciences and Advanced Technology in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran., Haddadi R; Department of Pharmacology and Toxicology, School of Pharmacy, Hamadan University of Medical Sciences, Hamadan, Iran., Sarihi A; Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran; Department of Neuroscience, School of Sciences and Advanced Technology in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran. Electronic address: sarihi@umsha.ac.ir.
Jazyk: angličtina
Zdroj: Pharmacology, biochemistry, and behavior [Pharmacol Biochem Behav] 2024 Jul; Vol. 240, pp. 173772. Date of Electronic Publication: 2024 Apr 21.
DOI: 10.1016/j.pbb.2024.173772
Abstrakt: The limbic system, particularly the NAc, shows a high concentration of metabotropic glutamate receptors (mGluRs). Recent evidence suggests the significant involvement of mGluRs in mental disorders, including substance abuse and addiction. The objective of this study was to examine the involvement of mGlu8 receptors in the NAc in the mechanisms underlying the extinction and reinstatement of conditioned place preference (CPP) induced by morphine. Male Wistar rats underwent surgical implantation of bilateral cannulas in the NAc and were assessed in a CPP protocol. In study 1 at the same time as the extinction phase, the rats were given varying doses of S-3,4-DCPG (0.03, 0.3, and 3 μg/0.5 μl). In study 2, rats that had undergone CPP extinction were given S-3,4-DCPG (0.03, 0.3, and 3 μg/0.5 μl) five minutes prior to receiving a subthreshold dose of morphine (1 mg/kg) in order to reactivate the previously extinguished morphine response. The findings demonstrated that administering S-3,4-DCPG directly into the accumbens nucleus resulted in a decrease in the duration of the CPP extinction phase. Moreover, dose-dependent administration of S-3,4-DCPG into the NAc inhibited CPP reinstatement. The observations imply that microinjection of S-3,4-DCPG as a potent orthosteric agonist with high selectivity for the mGlu8 receptor into the NAc promotes the process of extinction while concurrently exerting inhibitory effects on the reinstatement of morphine-induced CPP. This effect may be associated with the modulation of glutamate engagement within the NAc and the plasticity of reward pathways at the synaptic level.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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