#Opioid–galanin #receptor heteromers differentiate the #dopaminergic effects of #morphine and #methadone (J Clin Invest., abstract)

[Source: Journal of Clinical Investigation, full page: (LINK). Abstract, edited.]

Opioid–galanin receptor heteromers differentiate the dopaminergic effects of morphine and methadone

Randal A. Serafini and Venetia Zachariou

First published May 28, 2019

 

Abstract

As the opioid addiction crisis reaches epidemic levels, the identification of opioid analgesics that lack abuse potential may provide a path to safer treatment of chronic pain. Preclinical studies have demonstrated that galanin affects physical dependence and rewarding actions associated with morphine. In the brain and periphery, galanin and opioids signal through their respective GPCRs, GalR1–3 and the μ-opioid receptor (MOR). In this issue of the JCI, Cai and collaborators reveal that heteromers between GalR1 and MOR in the rat ventral tegmental area attenuate the potency of methadone, but not other opioids, in stimulating the dopamine release that produces euphoria. These studies help us understand why some synthetic opioids, such as methadone, do not trigger the release of dopamine in the mesolimbic system but still possess strong analgesic properties.

Keywords: Opioids; Dopamine; Neurology; Psychiatry.

——

Published by

Giuseppe Michieli

I am an Italian blogger, active since 2005 with main focus on emerging infectious diseases such as avian influenza, SARS, antibiotics resistance, and many other global Health issues. Other fields of interest are: climate change, global warming, geological and biological sciences. My activity consists mainly in collection and analysis of news, public services updates, confronting sources and making decision about what are the 'signals' of an impending crisis (an outbreak, for example). When a signal is detected, I follow traces during the entire course of an event. I started in 2005 my blog ''A TIME'S MEMORY'', now with more than 40,000 posts and 3 millions of web interactions. Subsequently I added an Italian Language blog, then discontinued because of very low traffic and interest. I contributed for seven years to a public forum (FluTrackers.com) in the midst of the Ebola epidemic in West Africa in 2014, I left the site to continue alone my data tracking job.