 |
| Research article summary (published 18 Feb 2009): |
Enhancing effects of morphine on methamphetamine-induced reinforcing behavior and its association with dopamine release and metabolism in mice.
Full Abstract
Polydrug abuse has become a significant problem worldwide, and the combined use of methamphetamine (MA) and morphine (M) is now highly prevalent among addicts. In the present study, we investigated the neurobehavioral effects of repeated treatment regimens of these drugs (i.p. administration of 0.75 mg/kg/day MA, 5 mg/kg/day M, and their combination for five consecutive days followed by once weekly for five consecutive weeks) in mice. In addition, we used an in vivo microdialysis technique to study the changes in extracellular concentrations of dopamine (DA) and its metabolites in the mouse striatum after challenge administration of these drugs. The results showed that systemic M increased MA-induced conditioned place preference (CPP), as revealed by higher CPP values which were also maintained for a longer duration compared with those induced by an identical dose of MA or M alone. Subsequent to challenge with combined MA and M, mice exhibited an increase in stereotyped behavior, which appeared to be associated with an elevation of extracellular concentration of DA in the striatum. Our findings suggest that M not only produces synergistic effects on MA-induced CPP, but also interacts with MA to induce stereotyped behavioral sensitization which is mediated by an increase in DA outflow in the striatum. These findings provide insight into the behavioral and neurochemical basis responsible for the combined abuse liability of MA and M.
Author information
Author/s: Lan, Kuo-Cheng (KC); Chang, Alice Chien (AC); Liu, Shing-Hwa (SH); Ho, Ing Kang (IK); Lin-Shiau, Shoei-Yn (SY);
Affiliation: Department of Emergency Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
Journal and publication information
Publication Type: Comparative Study; Journal Article; Research Support, Non-U.S. Gov't
Journal: Journal of neurochemistry (J Neurochem), published in England. (Language: eng)
Reference: 2009-Apr; vol 109 (issue 2) : pp 382-92
Dates: Created 2009/04/01; Completed 2009/04/24;
PMID: 19245664, status: MEDLINE (last retrieval date: 4/24/2009, IMS Date: 24 Apr 2009 00:00:00)
Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.
External Links for this article
(including full text providers, if available):
Click Electronic Full-text Provider Links to see options for finding the electronic full text links to this article. Note there may be a subscription or fee required for access to the full text. See our FAQ for information on finding FREE full text articles.
This article may also be located in paper journal collections available in many libraries. Use the Journal and Publication Information above to find the full article.
MeSH headings (categories)
This article was linked to the MESH Headings shown below.
Related articles
This article has not been indexed for related articles as yet, however you can still use the live related article search links below.
See a large map of 100+ related articles.