Featured Research

from universities, journals, and other organizations

Opioid abuse initiates specific protein interactions in neurons in brain’s reward system

Date:
February 24, 2014
Source:
Mount Sinai Medical Center
Summary:
Opiate use triggers changes in the protein RGS9-2 in neurons in the brain's reward center, new research confirms. Repeated use affects analgesic relief and tolerance, as well as addiction. Opioid addiction is widespread and this research underscores the deleterious effects of its use. According to the National Institute of Drug Abuse, in 2010, 1.9 million Americans satisfied abuse or dependence criteria for prescription opioids.

Identifying the specific pathways that promote opioid addiction, pain relief, and tolerance are crucial for developing more effective and less dangerous analgesics, as well as developing new treatments for addiction. Now, new research from the Icahn School of Medicine at Mount Sinai reveals that opiate use alters the activity of a specific protein needed for the normal functioning of the brain’s reward center.

Investigators were able to block the protein, as well as increase its expression in the mouse nucleus accumbens, a key component of the brain’s reward center. It altered the actions of opioids like morphine dramatically. The preclinical study, published online Feb. 24 in the journal Neuropsychopharmacology, is the first to show that opioid use changes activity of the protein RGS9-2 and alters both the threshold for pain relief and affects opioid tolerance.

“We were able to block addiction-related behaviors, but increasing the activity of the protein also lowered the pain relief response to morphine, and mice developed morphine tolerance much more quickly,” said the study’s senior researcher, Venetia Zachariou, PhD, Associate Professor, Fishberg Department of Neuroscience, Friedman Brain Institute, Department of Pharmacology and Systems Therapeutics, at the Icahn School of Medicine at Mount Sinai.

Dr. Zachariou explained that because the brain’s reward center has such a strong impact on analgesic responses, non-opioid medications should be used for the treatment of severe chronic pain conditions. Pain specialists have several alternatives for the treatment of chronic pain. For patients that are already addicted to opioids, “an alternative pain medication could offer more analgesic relief without the adverse effects of opioids.” Additionally, with this research in hand, the research team points out that targeting this molecule may eventually lead to a novel treatment for addiction.”

In the study, investigators used a novel technique known as optogenetics, which allows the activation of specific neurons via blue light in real time, to determine the exact cell types of the brain reward center responsible for the reduced analgesic response.

“In our earlier work, by inactivating RGS9-2, we saw a tenfold increase in sensitivity to the rewarding actions of morphine, severe morphine dependence, a better analgesic response, and delayed development of tolerance,” said the study’s senior author. While opiate analgesics act in several brain regions to alleviate pain, their actions in the brain reward center may also affect analgesia. The nucleus accumbens may also affect the development of morphine tolerance, via mechanism that are distinct from those described in other regions of the brain.

Eric Nestler, MD, PhD, Nash Family Professor of Neuroscience, Icahn School of Medicine at Mount Sinai, praised the research. “These discoveries provide important new information about the role of the brain reward pathway in the analgesic responses to opiates".

The study was carried out in collaboration with Mary Kay Lobo, PhD, from the University of Maryland, researchers from the University of Crete, and Karl Deisseroth, MD, PhD, from Stanford University, and coauthors from the Icahn School of Medicine.

Opioid addiction is widespread and this research underscores the deleterious effects of its use. According to the National Institute of Drug Abuse, in 2010, 1.9 million Americans satisfied abuse or dependence criteria for prescription opioids.


Story Source:

The above story is based on materials provided by Mount Sinai Medical Center. Note: Materials may be edited for content and length.


Journal Reference:

  1. Sevasti Gaspari, Maria M Papachatzaki, Ja Wook Koo, Fiona B Carr, Maria E Tsimpanouli, Eugenia Stergiou, Rosemary C Bagot, Deveroux Ferguson, Ezekiell Mouzon, Sumana Chakravarty, Karl Deisseroth, Mary Kay Lobo, Venetia Zachariou. Nucleus Accumbens Specific Interventions in RGS9-2 Activity Modulate Responses to Morphine. Neuropsychopharmacology, 2014; DOI: 10.1038/npp.2014.45

Cite This Page:

Mount Sinai Medical Center. "Opioid abuse initiates specific protein interactions in neurons in brain’s reward system." ScienceDaily. ScienceDaily, 24 February 2014. <www.sciencedaily.com/releases/2014/02/140224105836.htm>.
Mount Sinai Medical Center. (2014, February 24). Opioid abuse initiates specific protein interactions in neurons in brain’s reward system. ScienceDaily. Retrieved September 14, 2014 from www.sciencedaily.com/releases/2014/02/140224105836.htm
Mount Sinai Medical Center. "Opioid abuse initiates specific protein interactions in neurons in brain’s reward system." ScienceDaily. www.sciencedaily.com/releases/2014/02/140224105836.htm (accessed September 14, 2014).

Share This



More Mind & Brain News

Sunday, September 14, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Shocker: Journalists Are Utterly Addicted To Coffee

Shocker: Journalists Are Utterly Addicted To Coffee

Newsy (Sep. 13, 2014) A U.K. survey found that journalists consumed the most amount of coffee, but that's only the tip of the coffee-related statistics iceberg. Video provided by Newsy
Powered by NewsLook.com
'Magic Mushrooms' Could Help Smokers Quit

'Magic Mushrooms' Could Help Smokers Quit

Newsy (Sep. 11, 2014) In a small study, researchers found that the majority of long-time smokers quit after taking psilocybin pills and undergoing therapy sessions. Video provided by Newsy
Powered by NewsLook.com
'Fat Shaming' Might Actually Cause Weight Gain

'Fat Shaming' Might Actually Cause Weight Gain

Newsy (Sep. 11, 2014) A study for University College London suggests obese people who are discriminated against gain more weight than those who are not. Video provided by Newsy
Powered by NewsLook.com
Common Sleeping, Anxiety Pills Linked To Alzheimer's

Common Sleeping, Anxiety Pills Linked To Alzheimer's

Newsy (Sep. 10, 2014) Researchers found commonly prescribed sleeping and anxiety pills such as Xanax and Valium could lead to an increased risk for Alzheimer's disease. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

    Technology News



    Save/Print:
    Share:

    Free Subscriptions


    Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

    Get Social & Mobile


    Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

    Have Feedback?


    Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
    Mobile: iPhone Android Web
    Follow: Facebook Twitter Google+
    Subscribe: RSS Feeds Email Newsletters
    Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins