An Antisense Oligodeoxynucleotide to the Mu Opioid Receptor Attenuates Cocaine-induced Behavioral Sensitization and Reward in Mice.
From: Department of Pharmacology and the Center for Substance Abuse Research, Temple University School of Medicine, Philadelphia, PA 19140, USA. Hummelm2@wyeth.com
Neuroscience
- Publish Date: Oct 2006
- ISSN: 0306-4522
- Volume: 142
- Issue: 2
- Pages: 481-91
- Medium: Print
- Language: English
- Citation (JAMA): Hummel M, Schroeder J, Liu-Chen L-Y, et al. An Antisense Oligodeoxynucleotide to the Mu Opioid Receptor Attenuates Cocaine-induced Behavioral Sensitization and Reward in Mice.. Neuroscience Oct 2006;142:481-91
Abstract
Numerous studies support a role for the endogenous opioid system in cocaine-influenced behavior. Few of these studies, however, selectively delineate a role for the mu opioid receptor (MOR) in this regard. This investigation examined if the MOR modulates cocaine-induced behavior in mice using a 17-base antisense oligodeoxynucleotide (AS ODN) directed against the MOR coding sequence 16-32. Specifically, cocaine-induced behavioral sensitization and conditioned reward were investigated. For the sensitization study, C57BL/6J mice received eight intermittent i.c.v. infusions of saline, mismatch oligodeoxynucleotide (ODN) (20 microg/4 microl) or AS ODN (20 microg/4 microl) over 20 days. Mice also received concomitant once daily i.p. injections of saline (4 ml/kg) or cocaine (15 mg/kg) for 10 days. There was a 7-day withdrawal period, after which all mice were challenged with cocaine (15 mg/kg) to test for behavioral sensitization. For the conditioned place preference (CPP) study, mice received five i.c.v. infusions of mismatch ODN or MOR AS ODN (days 1-5). An unbiased counterbalanced conditioning procedure was used where mice were conditioned with saline (4 ml/kg, i.p.) and cocaine (15 mg/kg, i.p.) on alternate days for four sessions (days 3-6). Mice were tested on day 7 for CPP. Immediately following testing, [3H]DAMGO (D-Ala2, N-Me-Phe4, Gly-ol5-enkephalin) receptor binding to brain homogenates was conducted. MOR AS attenuated cocaine-induced behavioral sensitization and conditioned reward. MOR AS ODN also reduced [3H]DAMGO binding. Collectively, these findings implicate the MOR as playing an important neuromodulatory role in the behavioral effects of cocaine in mice.
Mesh Headings (Keywords): Analysis of Variance, Animals, Behavior, Animal, Cocaine-Related Disorders, Conditioning, Operant, Drug Administration Routes, Drug Interactions, Enkephalin, Ala(2)-MePhe(4)-Gly(5)-, Male, Mice, Mice, Inbred C57BL, Morphine, Narcotics, Oligodeoxyribonucleotides, Antisense, Protein Binding, Radiography, Receptors, Opioid, mu, Reward, Time Factors, Tritium
Check for Full Text / PubMed Unique Identifier (PMID): 16893609
This abstract is part of PubMed, a service of the U.S. National Library of Medicine. PubMed includes more than 17 million citations from MEDLINE and other life science journals for biomedical articles. See Copyright and Disclaimers.
Linked medical terms appearing on this page are added by Healia to help readers find more information and are not part of the original PubMed document.
The data herein was last updated on July 8th, 2008 and may not reflect the most current and accurate data available from NLM.