Featured Research

from universities, journals, and other organizations

Brain Releases Marijuana-Like Substance In Response To Pain, Study Finds

Date:
October 13, 1999
Source:
Brown University
Summary:
Pain triggers the brain’s release of a naturally produced cannabinoid, a compound similar to the active ingredient in marijuana, according to a new study by Brown researchers that documented its release in the brain’s pain response system for the first time.

PROVIDENCE, R.I. — Pain triggers the brain’s release of a naturally produced cannabinoid, a compound similar to the active ingredient in marijuana, according to a new study by Brown researchers that documented its release in the brain’s pain response system for the first time.

The cannabinoid known as anandamide produced analgesia – the absence of a normal sense of pain – in response to pain in anesthetized rats. The findings are published in the Oct. 12 issue of the Proceedings of the National Academy of Sciences (PNAS).

Although the existence of non-opiate factors in the brain’s pain suppression system were first noted 20 years ago, little was known about these substances. Brown researchers were able to measure the anandamide using a new type of mass spectrometry, which is able to detect minute amounts of a substance.

Knowledge about a pain-modulatory system based on cannabinoids is valuable for the future treatment of pain, particularly in instances where opiates are ineffective, according to J. Michael Walker, psychology professor and lead researcher.

“There are some types of pain that do not respond well to current treatments,” said Walker. “The fact that you have different modulatory systems that are effective for different types of pain may offer hope.”

Drugs that inhibit the reuptake of anandamide by cells, or block its degradation, may form the basis of a modern pharmacotherapy for pain, he said.

Researchers measured the levels of anandamide in the region of the brain recognized for its role in pain modulation – the periaqueductal gray (PAG). The PAG is part of the brain stem that connects the cerebral hemispheres with the spinal cord. It is very similar in animals and humans.

Electrical stimulation of the PAG in anesthetized animal models was accompanied by both pain suppression and a marked increase in the release of anandamide. Furthermore, injections of formalin, a chemical irritant that induces prolonged pain, profoundly elevated the anandamide levels in the same location of the PAG in anesthetized rats. Although animals did not feel the pain, researchers were able to observe pain modulation because the brain respond in the same way.

Researchers used atmospheric pressure-chemical ionization mass spectrometry to measure the molecular weight of anandamide. This multistep method permitted the detection of the extremely small amounts of the anandamide. They found the substance in a different location of the PAG than the location proven to play a part in the release of natural opiates.

“One of the functions of chemical transmission in the brain is to modify pain sensitivity, and the brain uses the anandamide for this purpose,” said Walker. “The pain itself triggers this reaction.”

The correlation between cannabinoids and pain suppression is not a startling finding in itself; cannabinoids have been used to treat pain for centuries. In ancient China, hemp extract was used as a surgical anesthetic, and archaeological finds in Israel have revealed its use against the pain of childbirth.

Cannabis is still used to treat pain, despite its illegal status in most parts of the world. A report early this year by the National Academy of Sciences Institute of Medicine found that significant amounts of research – including research by Walker and colleagues – point to the potential to use marijuana derivatives in treating chronic pain.

However, more research needs to be done to determine whether there are other naturally produced cannabinoids released in the brain in addition to anandamide, said Walker.

Other researchers involved in the study were Susan M. Huang, Brown graduate student; Nicole M. Strangman, Brown graduate student; M. Clara Sañudo-Peña, assistant research professor of psychology; and the late Brown University professor and member of the Chinese Academy of Sciences, Kang Tsou.

The work was supported with funding from the U.S. Public Health Service and National Institutes of Health. In addition, Brown University and the National Institute on Drug Abuse financed the purchase of the mass spectrometer used in the experiments.


Story Source:

The above story is based on materials provided by Brown University. Note: Materials may be edited for content and length.


Cite This Page:

Brown University. "Brain Releases Marijuana-Like Substance In Response To Pain, Study Finds." ScienceDaily. ScienceDaily, 13 October 1999. <www.sciencedaily.com/releases/1999/10/991013074947.htm>.
Brown University. (1999, October 13). Brain Releases Marijuana-Like Substance In Response To Pain, Study Finds. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/1999/10/991013074947.htm
Brown University. "Brain Releases Marijuana-Like Substance In Response To Pain, Study Finds." ScienceDaily. www.sciencedaily.com/releases/1999/10/991013074947.htm (accessed October 21, 2014).

Share This



More Health & Medicine News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

CDC Revamps Ebola Guidelines After Criticism

CDC Revamps Ebola Guidelines After Criticism

Newsy (Oct. 21, 2014) — The Centers for Disease Control and Prevention have issued new protocols for healthcare workers interacting with Ebola patients. Video provided by Newsy
Powered by NewsLook.com
WHO: Ebola Vaccine Trials to Start a in January

WHO: Ebola Vaccine Trials to Start a in January

AP (Oct. 21, 2014) — Tens of thousands of doses of experimental Ebola vaccines could be available for "real-world" testing in West Africa as soon as January as long as they are deemed safe in soon to start trials, the World Health Organization said Tuesday. (Oct. 21) Video provided by AP
Powered by NewsLook.com
First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

Newsy (Oct. 21, 2014) — A medical team has for the first time given a man the ability to walk again after transplanting cells from his brain onto his severed spinal cord. Video provided by Newsy
Powered by NewsLook.com
CDC Issues New Ebola Guidelines for Health Workers

CDC Issues New Ebola Guidelines for Health Workers

Reuters - US Online Video (Oct. 21, 2014) — The U.S. Centers for Disease Control and Prevention has set up new guidelines for health workers taking care of patients infected with Ebola. Linda So reports. Video provided by Reuters
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:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

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