Featured Research

from universities, journals, and other organizations

Brain Scans Prove Dopamine's Involvement In Cocaine Abuse

Date:
November 17, 1997
Source:
Johns Hopkins Medical Institutions
Summary:
Scientists at Johns Hopkins have used brain scans to show that intravenous doses of cocaine increase the availability of dopamine, the brain's "feel-good" chemical.

Scientists at Johns Hopkins have used brain scans to show that intravenous doses of cocaine increase the availability of dopamine, the brain's "feel-good" chemical. Dopamine's activity appeared to increase two to three times over baseline levels in the brain area studied, the putamen, compared to a control area, the cerebellum.

Although the increase cannot yet be directly linked to a cocaine user's "high," investigators report that this is the first time anyone has directly demonstrated that cocaine makes more dopamine available in the human brain.

Improvements in scanning technology eventually may track cocaine's effects on the dopamine-generating nucleus accumbens, a smaller area nearby in the brain that is known to play a role in addictive behavior in animals, adds Godfrey Pearlson, M.D., professor of psychiatry and a lead author on the paper.

"The new finding should advance efforts to understand addiction and treat it by blocking the euphoric effects of drugs," says Pearlson. Brain cells use dopamine by binding the chemical to specific openings on their surfaces. Pearlson used these openings to measure dopamine activity. First, he injected cocaine users with the compound raclopride, which binds to these same receptors. The raclopride was equipped with a mildly radioactive "tag" visible on positron emission tomography (PET) brain scans. Soon after, scientists gave the subjects an injection of a placebo and scanned their brains. Several hours later, the same subjects received a second dose of raclopride followed by a "street-equivalent" dose of cocaine. Then they scanned the patients again. "Because the raclopride and dopamine compete for the right to bind to the same receptors, we could compare the two sets of scans and be virtually certain that the differences in the second group were caused by extra dopamine produced by cocaine exposure," says Thomas Schlaepfer, M.D., now at the University of Bern in Switzerland. "It's likely cocaine affects other neurotransmitters besides dopamine, and these may also be helping create the immediate rush' or feeling of euphoria caused by cocaine," Pearlson explains. "But dopamine is still obviously a very important part of drug addiction. Marijuana, alcohol and heroin all initially act on different brain systems, but the common bond between them is that they all also increase dopamine availability."

The study, published with an accompanying commentary, in the September issue of the American Journal of Psychiatry, was funded by the National Institutes of Health, the Swiss National Science Foundation, the Roche Research Foundation, the CIBA Research Foundation, and other government and private sources.

Other authors were Dean Wong, M.D.; Stefano Marenco, M.D.; and Robert Dannals, Ph.D.


Story Source:

The above story is based on materials provided by Johns Hopkins Medical Institutions. Note: Materials may be edited for content and length.


Cite This Page:

Johns Hopkins Medical Institutions. "Brain Scans Prove Dopamine's Involvement In Cocaine Abuse." ScienceDaily. ScienceDaily, 17 November 1997. <www.sciencedaily.com/releases/1997/11/971117125133.htm>.
Johns Hopkins Medical Institutions. (1997, November 17). Brain Scans Prove Dopamine's Involvement In Cocaine Abuse. ScienceDaily. Retrieved August 22, 2014 from www.sciencedaily.com/releases/1997/11/971117125133.htm
Johns Hopkins Medical Institutions. "Brain Scans Prove Dopamine's Involvement In Cocaine Abuse." ScienceDaily. www.sciencedaily.com/releases/1997/11/971117125133.htm (accessed August 22, 2014).

Share This




More Health & Medicine News

Friday, August 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Newsy (Aug. 21, 2014) An experimental drug used to treat Marburg virus in rhesus monkeys could give new insight into a similar treatment for Ebola. Video provided by Newsy
Powered by NewsLook.com
Two US Ebola Patients Leave Hospital Free of the Disease

Two US Ebola Patients Leave Hospital Free of the Disease

AFP (Aug. 21, 2014) Two American missionaries who were sickened with Ebola while working in Liberia and were treated with an experimental drug are doing better and have left the hospital, doctors say on August 21, 2014. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
Cadavers, a Teen, and a Medical School Dream

Cadavers, a Teen, and a Medical School Dream

AP (Aug. 21, 2014) Contains graphic content. He's only 17. But Johntrell Bowles has wanted to be a doctor from a young age, despite the odds against him. He was recently the youngest participant in a cadaver program at the Indiana University NW medical school. (Aug. 21) Video provided by AP
Powered by NewsLook.com
American Ebola Patients Released: What Cured Them?

American Ebola Patients Released: What Cured Them?

Newsy (Aug. 21, 2014) It's unclear whether the American Ebola patients' recoveries can be attributed to an experimental drug or early detection and good medical care. 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