Featured Research

from universities, journals, and other organizations

Mice Provide Important Clues To Obsessive-compulsive Disorder

Date:
August 26, 2007
Source:
Duke University Medical Center
Summary:
Mice born without a key brain protein compulsively groom their faces until they bleed and are afraid to venture out of the corner of their cages. When given a replacement dose of the protein in a specific region of the brain, or the drugs used to treat humans suffering from obsessive-compulsive disorder, many of these mice seem to get better.

SAPAP3 knockout mouse has a raw bald patch on its face from compulsive grooming behavior.
Credit: Guoping Feng, Ph.D., Duke University

Mice born without a key brain protein compulsively groom their faces until they bleed and are afraid to venture out of the corner of their cages. When given a replacement dose of the protein in a specific region of the brain, or the drugs used to treat humans suffering from obsessive-compulsive disorder (OCD), many of these mice seem to get better.

Duke University Medical Center investigators, in their basic research into how individual brain cells communicate with each other, discovered serendipitously that mice with a genetic mutation that prevents their brain cells from producing one key protein exhibited OCD-like behavior.

The finding may have uncovered important clues about a possible mechanism for OCD, a debilitating psychiatric condition affecting up to 2 percent of the world's people.

The international team of researchers, led by Duke molecular geneticist Guoping Feng, Ph.D., reported its findings in the August 23 issue of the journal Nature. The research was supported by the National Institutes of Health, the McKnight Endowment Fund for Neuroscience, and the Hartwell Foundation.

"The mice that could not produce this protein exhibited behaviors similar to that of humans with OCD, a compulsive action coupled with increased anxiety," Feng said. "We obviously cannot talk to mice to find out what they are thinking, but these mutant mice clearly did things that looked like OCD."

OCD is one of the most common psychiatric disorders in the world. It is marked by persistent intrusive thoughts (the obsession), repetitive actions (the compulsion) and anxiety. The severity OCD varies widely from person to person, and while the neurobiological basis of the disease is unknown, there are indications that genetics play a role, Feng said.

In their experiments, the Duke team focused on a portion of the brain known as the striatum, an area that controls the planning and execution of movement, as well as other cognitive functions. It is in many ways "the decider." In normal brains, a protein known as SAPAP3 is crucial for nerve signals to travel from one nerve cell to another across the synapse, the gap between the cells.

"This protein is important for allowing messages to cross synapses, and it is produced at high levels in the cells that make up the striatum," Feng explained. "When we looked closely at the brain cells of these mutant mice, we found that there were defects in the synapses.

"When we returned the protein into the striatum of brains of the mutant mice, the synaptic defects were repaired and their OCD-like behaviors subsided," Feng continued. "This is the first direct evidence that a synaptic defect in the striatum caused these OCD-like behaviors."

The researchers also found that a class of drugs known as selective serotonin reuptake inhibitors (SSRI) reduced the anxiety levels and suppressed the over-grooming in the mutant mice, further suggesting that what they observed in mice may also be analogous to human OCD. Serotonin, like SAPAP3, is one of many neurotransmitters, chemicals involved in nerve cell communication.

While SSRIs are the most commonly prescribed drug for humans with OCD, they are only effective for about half the patients, suggesting to Feng that many pathways involving different neurotransmitters are likely involved.

Feng and other colleagues at Duke are currently looking for additional gene variations that may affect how nerve signals cross synapses, and they are also beginning studies to determine if the gene mutant they discovered in mice plays a role in humans with OCD.

For this study, Feng collaborated with William Wetsel and Nicole Calakos from Duke University; Richard Weinberg from University of North Carolina at Chapel Hill; Serena Dudek from the National Institute of Environmental Health Sciences; as well as researchers from Zhejiang University School of Medicine, China; University of Coimbra, Portugal; and Gulbenkian Science Institute, Portugal.


Story Source:

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


Cite This Page:

Duke University Medical Center. "Mice Provide Important Clues To Obsessive-compulsive Disorder." ScienceDaily. ScienceDaily, 26 August 2007. <www.sciencedaily.com/releases/2007/08/070822132156.htm>.
Duke University Medical Center. (2007, August 26). Mice Provide Important Clues To Obsessive-compulsive Disorder. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2007/08/070822132156.htm
Duke University Medical Center. "Mice Provide Important Clues To Obsessive-compulsive Disorder." ScienceDaily. www.sciencedaily.com/releases/2007/08/070822132156.htm (accessed July 23, 2014).

Share This




More Mind & Brain News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Why Do People Believe We Only Use 10 Percent Of Our Brains?

Why Do People Believe We Only Use 10 Percent Of Our Brains?

Newsy (July 22, 2014) The new sci-fi thriller "Lucy" is making people question whether we really use all our brainpower. But, as scientists have insisted for years, we do. Video provided by Newsy
Powered by NewsLook.com
Do Obese Women Have 'Food Learning Impairment'?

Do Obese Women Have 'Food Learning Impairment'?

Newsy (July 18, 2014) Yale researchers tested 135 men and women, and it was only obese women who were deemed to have "impaired associative learning." Video provided by Newsy
Powered by NewsLook.com
Does Mixing Alcohol and Energy Drinks Boost Urge To Drink?

Does Mixing Alcohol and Energy Drinks Boost Urge To Drink?

Newsy (July 18, 2014) A new study suggests that mixing alcohol with energy drinks makes you want to keep the party going. Video provided by Newsy
Powered by NewsLook.com
Pot Cooking Class Teaches Responsible Eating

Pot Cooking Class Teaches Responsible Eating

AP (July 18, 2014) Following the nationwide trend of eased restrictions on marijuana use, pot edibles are growing in popularity. One Boston-area cooking class is teaching people how to eat pot responsibly. (July 18) 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:
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