- 作者: Robin W. Rockhold; Niansen Liu; Dominick Coleman; Stephen Commiskey; Jonathan Shook; Ing K. Ho
- 作者服務機構: Department of Pharmacology and Toxicology and Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Miss., USA
- 中文摘要: --
- 英文摘要: Participation of the nucleus paragigantocellularis (PGi) inmediation of opioid withdrawal was examined in con-scious, unrestrained, non-opioid-dependent rats, usingelectrical stimulation of the PGi. A characteristic series ofbehaviors, which resembled those seen during nalox-one-precipitated withdrawal from dependence on theopioid agonist, butorphanol, was elicited during 30 minof PGi stimulation. Thus, the behavioral syndrome hasbeen termed opioid withdrawal-like. Simultaneous mi-crodialysis measurement of glutamate within the locusceruleus indicated a positive correlation between extra-cellular glutamate concentrations and behavioral re-sponses. Behavioral responses were inhibited by 50%during reverse dialysis perfusion of the locus ceruleuswith the glutamate receptor antagonist, kynurenic acid,without any effect on glutamate concentrations. Thus,increases in locus ceruleus glutamate partially mediateopioid withdrawal-like behavior. Intracerebroventricular(i.c.v.) injections of the opioid antagonist, naloxone, or ofthe μ-selective (β-funaltrexamine) or the δ-selective (nal-trindole) opioid antagonists decreased, but did not abol-ish, stimulation-induced behavioral responses. Similari.c.v. injections of the κ-selective antagonist, nor-binal-torphimine, had no effect on behavioral responsesto PGistimulation. Activation of the PGi by electrical stimula-tion can elicit behaviors similarto those observed duringopioid withdrawal. Moreover, additional levels of com-plexity are evident in the neuropharmacology of PGistimulation-induced opioid withdrawal-like behavior.
- 中文關鍵字: --
- 英文關鍵字: --