alexa Motivational state determines the functional role of the mesolimbic dopamine system in the mediation of opiate reward processes.


Journal of Addiction Research & Therapy

Author(s): Laviolette SR, Nader K, van der Kooy D

Abstract Share this page

Abstract We have previously reported that mesolimbic dopamine (DA) substrates are critically involved in the rewarding effects of opiates only during states of opiate-dependence and withdrawal. However, in previously drug-naive animals, opiate reward is mediated through a DA-independent neural system. In the present study, we report that bilateral microinjections of a DA receptor antagonist, alpha-flupenthixol (0.3-3 microg/0.5 microl) into the nucleus accumbens (NAc), blocks morphine reward (10 mg/kg, i.p.) in opiate-withdrawn animals, but not in opiate-naive animals, suggesting that accumbal dopamine receptors are required for opiate reward signaling in drug-deprived motivational states. Next, the role of dopamine was examined in the development of opiate dependence and somatic withdrawal, and expression of withdrawal aversions. Pretreatment with alpha-flupenthixol (0.8 mg/kg, i.p.) before morphine injections during the development of opiate dependence did not effect expression of withdrawal aversions or the expression of somatic withdrawal. We have previously reported that pretreatment with a dopamine receptor antagonist, alpha-flupenthixol, blocks the aversive effects of opiate withdrawal. We now report that pretreatment with a direct dopamine receptor agonist, apomorphine (1.0-5.0 mg/kg, i.p.) before conditioning in a state of withdrawal, also blocks the aversive effects of opiate withdrawal. We propose that the aversive motivational effects of opiate withdrawal may be mediated by a specific dopaminergic neuronal signal.
This article was published in Behav Brain Res and referenced in Journal of Addiction Research & Therapy

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

Relevant Topics

Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version