Featured Research

from universities, journals, and other organizations

Cocaine Use Decreases Ability To Respond To Stimulation, Yale Researchers Find

Date:
February 27, 2001
Source:
Yale University
Summary:
Using an innovative method called transcranial magnetic stimulation (TMS) to measure brain responsiveness, Yale researchers have found that a cocaine addict’s response to stimulation is decreased, indicating possible evidence that cocaine causes permanent brain damage.

Using an innovative method called transcranial magnetic stimulation (TMS) to measure brain responsiveness, Yale researchers have found that a cocaine addict’s response to stimulation is decreased, indicating possible evidence that cocaine causes permanent brain damage.

"Contrary to what we expected, the results showed that cocaine-dependent individuals displayed increased resistance to brain stimulation," said Nashaat Boutros, associate professor of psychiatry at Yale and principal investigator on the study. "We expected them to be jumpy or more responsive because of the sensitizing effects of cocaine, but it took much stronger stimulation to get them to respond."

Boutros and his team examined 10 cocaine-dependent subjects (four men and six women) who had not used cocaine for at least three weeks and were addicted to no other drugs. A magnetic stimulus was delivered by TMS using a hand-held magnetic coil over the motor cortex, the part of the brain that moves the hands and fingers. The amount of magnetic stimulus needed to move the fingers is an indication of sensitivity in that part of the brain.

The results, published in the February 15 issue of Biological Psychiatry, showed that those without cocaine addiction need about 35 to 55 percent of the output to move their fingers. Boutros said cocaine-addicted individuals sometimes need as much as 80 percent. "Somehow addicts have increased their resistance to the effect of the stimulus," Boutros said.

Boutros and his team started out with the theory that the longer people use cocaine, the more it causes symptoms like paranoia, panic attacks and seizures. "People have thought that a process called kindling—over time, less stimulus is needed to elicit the same response—would apply to cocaine addicts," Boutros said. "But these results raise other possibilities."

Boutros believes there are two possible theories that could explain the findings. One is that the cocaine caused widespread damage that decreased the brain’s ability to respond to stimulation. "The other possibility," Boutros said, "is that the brain was indeed sensitized via the kindling response, and what we’re seeing is a normal response from the brain, like an overcompensation. The brain feels too sensitive from all the cocaine jitter and cools off the response."

A follow-up study, Boutros said, will confirm this initial finding by examining a different group of cocaine-addicted people using additional TMS techniques. TMS has been used to study neurological disorders for 10 years, but was first used in exploration of cortical function in psychiatric disorders about three years ago.


Story Source:

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


Cite This Page:

Yale University. "Cocaine Use Decreases Ability To Respond To Stimulation, Yale Researchers Find." ScienceDaily. ScienceDaily, 27 February 2001. <www.sciencedaily.com/releases/2001/02/010223080732.htm>.
Yale University. (2001, February 27). Cocaine Use Decreases Ability To Respond To Stimulation, Yale Researchers Find. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/2001/02/010223080732.htm
Yale University. "Cocaine Use Decreases Ability To Respond To Stimulation, Yale Researchers Find." ScienceDaily. www.sciencedaily.com/releases/2001/02/010223080732.htm (accessed October 1, 2014).

Share This



More Mind & Brain News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Pregnancy Spacing Could Have Big Impact On Autism Risks

Pregnancy Spacing Could Have Big Impact On Autism Risks

Newsy (Oct. 1, 2014) A new study says children born less than one year and more than five years after a sibling can have an increased risk for autism. Video provided by Newsy
Powered by NewsLook.com
Stopping School Violence

Stopping School Violence

Ivanhoe (Oct. 1, 2014) A trauma doctor steps out of the hospital and into the classroom to teach kids how to calmly solve conflicts, avoiding a trip to the ER. Video provided by Ivanhoe
Powered by NewsLook.com
Pineal Cysts: Debilitating Pain

Pineal Cysts: Debilitating Pain

Ivanhoe (Oct. 1, 2014) A tiny cyst in the brain that can cause debilitating symptoms like chronic headaches and insomnia, and the doctor who performs the delicate surgery to remove them. Video provided by Ivanhoe
Powered by NewsLook.com
Burning Away Brain Tumors

Burning Away Brain Tumors

Ivanhoe (Oct. 1, 2014) Doctors are 'cooking' brain tumors. Hear how this new laser-heat procedure cuts down on recovery time. Video provided by Ivanhoe
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