Featured Research

from universities, journals, and other organizations

Brain Shows Ability To Recover From Some Methamphetamine Damage

Date:
December 6, 2001
Source:
Brookhaven National Laboratory
Summary:
A new brain-imaging study at the U.S. Department of Energy's Brookhaven National Laboratory indicates that some of the damage caused by methamphetamine -- a drug abused by ever-increasing numbers of Americans -- can be reversed by prolonged abstinence from the drug.

UPTON, NY -- A new brain-imaging study at the U.S. Department of Energy's Brookhaven National Laboratory indicates that some of the damage caused by methamphetamine -- a drug abused by ever-increasing numbers of Americans -- can be reversed by prolonged abstinence from the drug. The results appear in the December 1, 2001 issue of The Journal of Neuroscience.

"Methamphetamine is a particularly problematic, highly addictive drug," said Nora Volkow, who led the study with Linda Chang. Their team had previously shown that methamphetamine abusers have significantly depleted levels of dopamine transporters. These proteins, found on the terminals of some brain cells, recycle dopamine, a brain chemical associated with pleasure and reward and also essential for movement. The study also found that meth abusers had impaired cognitive and motor function (see http://www.bnl.gov/bnlweb/pubaf/pr/bnlpr030101.htm).

"These changes could mean that meth abusers would be predisposed to such neurodegenera-tive disorders as Parkinson’s disease, which is also characterized by problems with dopamine and motor function," Volkow said. "It depends in part on whether the damage is reversible."

To help answer this question, Volkow and her team used positron emission tomography, or PET scanning, to measure the level of dopamine transporters in methamphetamine abusers after varying periods of abstinence. One group of 12 methamphetamine abusers was scanned within 6 months of taking the drug, and, for 5 of these subjects who managed to stay drug-free, the scan was repeated after 9 months of abstinence. Another group of 5 methamphetamine abusers was studied only after 9 months of abstinence. All subjects were compared with normal controls.

For each scan, each study volunteer was given an injection carrying a radiotracer, a radioactive chemical "tag" designed to bind to dopamine transporters in the brain. The researchers then scanned the subjects' brains using a PET camera, which picks up the radioactive signal of the tracer bound to the transporters. The strength of the signal indicates the number of transporters.

The scientists also looked for improvements in cognitive and motor function after abstinence by administering a battery of neuropsychological tests. These included tests of fine and gross motor function and tests of attention and memory.

The main finding was that, in methamphetamine abusers who were able to stay drug-free for at least 9 months, dopamine transporter levels showed significant improvement, approaching the level observed in control subjects. In abusers studied within 6 and after 9 months, the longer the period between the first and second evaluation, the larger the increase in dopamine transporter levels. Cognitive and motor function showed a trend toward improvement on some tests, but these changes were not statistically significant.

"The increase in dopamine transporter levels with prolonged abstinence indicates that the terminals of dopamine-secreting cells, which are thought to be damaged by methamphetamine abuse, are able to regenerate," Volkow said. Another possibility is that other, undamaged terminals are able to branch out and make up for the loss.

"These findings have implications for the treatment of methamphetamine abusers because they suggest that protracted abstinence and proper rehabilitation may reverse some of the meth-induced alterations in dopamine cells," Volkow said. "Unfortunately, we did not see a parallel improvement in function."

The recovery of dopamine transporters may not have been sufficient to completely make up for the damage to the dopamine terminals, she suggested. Additionally, other systems necessary for neuropsychological function might also be damaged by the drug — and less able to recover. Also, Volkow noted, the sample sizes were small. "Further study in larger samples is required to assess whether recovery of dopamine transporters with protracted abstinence is associated with recovery of neuropsychological function," she said.

This work was funded by the U.S. Department of Energy, which supports basic research in a variety of scientific fields; the National Institute on Drug Abuse; the National Institutes of Health; and the Office of National Drug Control Policy.

The U.S. Department of Energy's Brookhaven National Laboratory (http://www.bnl.gov) conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies. Brookhaven also builds and operates major facilities available to university, industrial, and government scientists. The Laboratory is managed by Brookhaven Science Associates, a limited liability company founded by Stony Brook University and Battelle, a nonprofit applied science and technology organization.


Story Source:

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


Cite This Page:

Brookhaven National Laboratory. "Brain Shows Ability To Recover From Some Methamphetamine Damage." ScienceDaily. ScienceDaily, 6 December 2001. <www.sciencedaily.com/releases/2001/12/011203060457.htm>.
Brookhaven National Laboratory. (2001, December 6). Brain Shows Ability To Recover From Some Methamphetamine Damage. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/2001/12/011203060457.htm
Brookhaven National Laboratory. "Brain Shows Ability To Recover From Some Methamphetamine Damage." ScienceDaily. www.sciencedaily.com/releases/2001/12/011203060457.htm (accessed October 20, 2014).

Share This



More Health & Medicine News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

How Nigeria Beat Its Ebola Outbreak

How Nigeria Beat Its Ebola Outbreak

Newsy (Oct. 20, 2014) The World Health Organization has declared Nigeria free of Ebola. Health experts credit a bit of luck and the government's initial response. Video provided by Newsy
Powered by NewsLook.com
Another Study Suggests Viagra Is Good For The Heart

Another Study Suggests Viagra Is Good For The Heart

Newsy (Oct. 20, 2014) An ingredient in erectile-dysfunction medications such as Viagra could improve heart function. Perhaps not surprising, given Viagra's history. Video provided by Newsy
Powered by NewsLook.com
Ebola Worries End for Dozens on U.S. Watch Lists

Ebola Worries End for Dozens on U.S. Watch Lists

Reuters - US Online Video (Oct. 20, 2014) Forty-three people who had contact with Thomas Eric Duncan, the first person diagnosed with Ebola in the U.S., were cleared overnight of twice-daily monitoring after 21 days of showing no symptoms. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
CDC Calls for New Ebola Safety Guidelines

CDC Calls for New Ebola Safety Guidelines

AP (Oct. 20, 2014) Centers for Disease Control and Prevention Director Dr. Tom Frieden laid out new guidelines for health care workers when dealing with the deadly Ebola virus including new precautions when taking off personal protective equipment. (Oct. 20) Video provided by AP
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