Featured Research

from universities, journals, and other organizations

Developmental delay in brain provides clue to sensory hypersensitivity in autism

Date:
February 10, 2010
Source:
Cell Press
Summary:
New research provides insight into why fragile X syndrome, the most common known cause of autism and mental retardation, is associated with an extreme hypersensitivity to sounds, touch, smells, and visual stimuli that causes sensory overload and results in social withdrawal, hyperarousal, and anxiety. The study uncovers a previously unknown developmental delay in a critical brain circuit that processes sensory information in a mouse model of fragile X syndrome.

New research provides insight into why fragile X syndrome, the most common known cause of autism and mental retardation, is associated with an extreme hypersensitivity to sounds, touch, smells, and visual stimuli that causes sensory overload and results in social withdrawal, hyperarousal, and anxiety. The study, published by Cell Press in the February 11 issue of the journal Neuron, uncovers a previously unknown developmental delay in a critical brain circuit that processes sensory information in a mouse model of fragile X syndrome.

Related Articles


Fragile X syndrome is caused by a mutation that interferes with production of fragile X mental retardation protein (FMRP). FMRP has been shown to play a key role in neuronal development and plasticity, and the loss of FMRP results in the complex and severely debilitating symptoms associated with fragile X syndrome.

"A central feature of fragile X syndrome is an alteration in sensory processing that manifests in early infancy and progressively worsens through childhood," explains senior study author, Dr. Anis Contractor from the Department of Physiology at the Northwestern Feinberg School of Medicine in Chicago. "Little is known about how disruptions in the part of the brain that process sensory information, called the sensory cortex, contribute to these deficits."

Dr. Contractor and colleagues used a mouse model of fragile X syndrome that exhibits hypersensitivity to sensory stimuli, similar to the human syndrome, to examine the development of synapses in the sensory cortex. Synapses are the sites of communication between neurons, and the ability of the brain to correctly process incoming information is predicated on the correct development of these structures. Although previous work had shown that there are clear defects in the size, shape, and number of synapses in the sensory cortex of fragile X mice, it was not clear whether the abnormalities had any functional impact on the development of the sensory cortex.

During perinatal development in the normal mouse, there is an activity-dependent maturation of synapses. This sensory-driven maturation of key synapses must occur at the right time, called the "critical period." The researchers found that the fragile X mice exhibited a profoundly altered development of synapses in the part of the mouse cortex that processes sensory information from the whiskers. Loss of FMRP resulted in a dysregulation of synapse maturation so that there was a delay in the normal window for synaptic plasticity.

"The precise timing of critical periods during cortical development is essential for the proper organization of synaptic connections and circuits," says Dr. Contractor. "The delayed timing of plasticity windows we observed might contribute to the altered refinement of cortical circuits that persist throughout the life of the animal and contribute to sensory processing deficits in fragile X syndrome."

The researchers include Emily G. Harlow, Northwestern University Feinberg School of Medicine, Chicago, IL; Sally M. Till, University of Edinburgh, Edinburgh, UK; Theron A. Russell, Northwestern University Feinberg School of Medicine, Chicago, IL; Lasani S. Wijetunge, University of Edinburgh, Edinburgh, UK; Peter Kind, University of Edinburgh, Edinburgh, UK; and Anis Contractor, Northwestern University Feinberg School of Medicine, Chicago, IL.


Story Source:

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


Cite This Page:

Cell Press. "Developmental delay in brain provides clue to sensory hypersensitivity in autism." ScienceDaily. ScienceDaily, 10 February 2010. <www.sciencedaily.com/releases/2010/02/100210124755.htm>.
Cell Press. (2010, February 10). Developmental delay in brain provides clue to sensory hypersensitivity in autism. ScienceDaily. Retrieved January 29, 2015 from www.sciencedaily.com/releases/2010/02/100210124755.htm
Cell Press. "Developmental delay in brain provides clue to sensory hypersensitivity in autism." ScienceDaily. www.sciencedaily.com/releases/2010/02/100210124755.htm (accessed January 29, 2015).

Share This


More From ScienceDaily



More Health & Medicine News

Thursday, January 29, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Malnutrition on the Rise as Violence Flares in C. Africa

Malnutrition on the Rise as Violence Flares in C. Africa

AFP (Jan. 28, 2015) Violence can flare up at any moment in Bambari with only a bridge separating Muslims and Christians. Malnutrition is on the rise and lack of water means simple cooking fires threaten to destroy makeshift camps where people are living. Duration: 00:40 Video provided by AFP
Powered by NewsLook.com
Poultry Culled in Taiwan to Thwart Bird Flu

Poultry Culled in Taiwan to Thwart Bird Flu

Reuters - News Video Online (Jan. 28, 2015) Taiwan culls over a million poultry in efforts to halt various strains of avian flu. Julie Noce reports. Video provided by Reuters
Powered by NewsLook.com
Media Criticizing Parents For Not Vaccinating Children

Media Criticizing Parents For Not Vaccinating Children

Newsy (Jan. 28, 2015) As the Disneyland measles outbreak continues to spread, the media says parents who choose not to vaccinate their children are part of the cause. Video provided by Newsy
Powered by NewsLook.com
Shark Bite Victim Making Amazing Recovery

Shark Bite Victim Making Amazing Recovery

AP (Jan. 27, 2015) A Texas woman who lost more than five pounds of flesh to a shark in the Bahamas earlier this month could be released from a Florida hospital soon. Experts believe she was bitten by a bull shark while snorkeling. (Jan. 27) 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