Featured Research

from universities, journals, and other organizations

Mechanisms Of Common Inherited Mental Retardation Uncovered

Date:
January 9, 2008
Source:
UT Southwestern Medical Center
Summary:
Researchers are uncovering how brain cells are affected in Fragile X syndrome, the most common cause of inherited mental retardation and the most common genetic cause of autism. "I think we've discovered a core mechanism underlying Fragile X syndrome," said the senior author of the study.

Dr. Kimberly Huber investigated how Fragile X syndrome affects communication between cells in the hippocampus, a region of the brain that is involved in learning and memory.
Credit: Image courtesy of UT Southwestern Medical Center

Researchers at UT Southwestern Medical Center are uncovering how brain cells are affected in Fragile X syndrome, the most common cause of inherited mental retardation and the most common genetic cause of autism.

“I think we’ve discovered a core mechanism underlying Fragile X syndrome,” said Dr. Kimberly Huber, assistant professor of neuroscience and senior author of a study appearing in the Journal of Neuroscience January 9.

Dr. Huber’s research with mice focuses on how Fragile X syndrome affects communication between cells in the hippocampus, a region of the brain that is involved in learning and memory. Her findings show that two different chemical signals go awry in Fragile X syndrome, indicating that drugs that interact with these signals might be a pathway to help treat the syndrome.

“The more we know about how signaling mechanisms in the brain lead to normal memory and learning, the better we can understand what goes wrong in conditions such as Fragile X syndrome,” said Dr. Huber, who is a Southwestern Medical Foundation Scholar in Medical Research. “Our research is laying the groundwork for such understanding and indicates a new area for research.”

Fragile X syndrome got its name because it affects a single gene, Fmr1, on the X chromosome. Under a microscope, the area around the gene looks narrower than normal, or “fragile.” According to the Centers for Disease Control and Prevention, the syndrome, which mostly occurs in males, affects about one in every 4,000 white males in the U.S.

It often causes a distinct physical appearance including an elongated face with protruding ears, hyperflexible joints, and mental deficits ranging from mood disorders to severe mental retardation. Much of the current treatment focuses on behavioral therapy combined with medications to control mood and seizures.

Dr. Huber previously co-discovered that mice genetically engineered to lack Fmr1 have a defective signaling system in the brain that controls learning in the hippocampus. This system relies on a chemical messenger called glutamate, which under normal circumstances causes nerve cells to make proteins and change their electrical firing patterns in response to learning situations. Without a properly working Fmr1 gene, the glutamate signaling system malfunctions.

In 2007 she and colleagues at UT Southwestern found that acetylcholine, another specific signaling chemical, affects the same protein-making factory that glutamate does. This research appeared in the Oct. 24, 2007, issue of the Journal of Neuroscience.

“We suggest that treatment that affects the acetylcholine system might be a supplement or alternative to drugs targeting the glutamate pathway,” Dr. Huber said.

In the current study, she and postdoctoral researcher Dr. Jennifer Ronesi investigated a protein, called Homer, which serves as a kind of structural support for the glutamate system. The Homer–glutamate support system is disconnected in Fragile X syndrome. Dr. Huber’s group discovered that this disconnection results in an inability of brain cells to make the new proteins important for learning and memory.

“These results show that Homer plays a vital role making proteins and learning, so it may also indicate where we could target drugs,” Dr. Huber said.

The current study was supported by the National Institutes of Health and FRAXA Research Foundation.


Story Source:

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


Cite This Page:

UT Southwestern Medical Center. "Mechanisms Of Common Inherited Mental Retardation Uncovered." ScienceDaily. ScienceDaily, 9 January 2008. <www.sciencedaily.com/releases/2008/01/080108183029.htm>.
UT Southwestern Medical Center. (2008, January 9). Mechanisms Of Common Inherited Mental Retardation Uncovered. ScienceDaily. Retrieved April 20, 2014 from www.sciencedaily.com/releases/2008/01/080108183029.htm
UT Southwestern Medical Center. "Mechanisms Of Common Inherited Mental Retardation Uncovered." ScienceDaily. www.sciencedaily.com/releases/2008/01/080108183029.htm (accessed April 20, 2014).

Share This



More Health & Medicine News

Sunday, April 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Nine-Month-Old Baby Can't Open His Mouth

Nine-Month-Old Baby Can't Open His Mouth

Newsy (Apr. 19, 2014) Nine-month-old Wyatt Scott was born with a rare disorder called congenital trismus, which prevents him from opening his mouth. Video provided by Newsy
Powered by NewsLook.com
'Holy Grail' Of Weight Loss? New Find Could Be It

'Holy Grail' Of Weight Loss? New Find Could Be It

Newsy (Apr. 18, 2014) In a potential breakthrough for future obesity treatments, scientists have used MRI scans to pinpoint brown fat in a living adult for the first time. Video provided by Newsy
Powered by NewsLook.com
Little Progress Made In Fighting Food Poisoning, CDC Says

Little Progress Made In Fighting Food Poisoning, CDC Says

Newsy (Apr. 18, 2014) A new report shows rates of two foodborne infections increased in the U.S. in recent years, while salmonella actually dropped 9 percent. Video provided by Newsy
Powered by NewsLook.com
Scientists Create Stem Cells From Adult Skin Cells

Scientists Create Stem Cells From Adult Skin Cells

Newsy (Apr. 17, 2014) The breakthrough could mean a cure for some serious diseases and even the possibility of human cloning, but it's all still a way off. 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