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.

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 August 29, 2014 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 August 29, 2014).

Share This




More Health & Medicine News

Friday, August 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

3 Things To Know About The Ebola Outbreak's Progression

3 Things To Know About The Ebola Outbreak's Progression

Newsy (Aug. 29, 2014) Here are three things you need to know about the deadly Ebola outbreak's progression this week. Video provided by Newsy
Powered by NewsLook.com
Killer Amoeba Found in Louisiana Water System

Killer Amoeba Found in Louisiana Water System

AP (Aug. 28, 2014) State health officials say testing has confirmed the presence of a killer amoeba in a water system serving three St. John the Baptist Parish towns. (Aug. 28) Video provided by AP
Powered by NewsLook.com
Who Could Be Burnt by WHO's E-Cigs Move?

Who Could Be Burnt by WHO's E-Cigs Move?

Reuters - Business Video Online (Aug. 28, 2014) The World Health Organisation has called for the regulation of electronic cigarettes as both tobacco and medical products. Ciara Lee looks at the impact of the move on the tobacco industry. Video provided by Reuters
Powered by NewsLook.com
CDC Director On Ebola Outbreak: 'It's Worse Than I Feared'

CDC Director On Ebola Outbreak: 'It's Worse Than I Feared'

Newsy (Aug. 28, 2014) CDC director Tom Frieden says the Ebola outbreak is even worse than he feared. But he also said there's still hope to contain it. 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