Navigation Links
Autism changes molecular structure of the brain, UCLA study finds
Date:5/25/2011

For decades, autism researchers have faced a baffling riddle: how to unravel a disorder that leaves no known physical trace as it develops in the brain.

Now a UCLA study is the first to reveal how the disorder makes its mark at the molecular level, resulting in an autistic brain that differs dramatically in structure from a healthy one. Published May 25 in the advance online edition of Nature, the findings provide new insight into how genes and proteins go awry in autism to alter the mind.

The discovery also identifies a new line of attack for researchers, who currently face a vast array of potential fronts for tackling the neurological disease and identifying its diverse causes.

"If you randomly pick 20 people with autism, the cause of each person's disease will be unique," said principal investigator Dr. Daniel Geschwind, the Gordon and Virginia MacDonald Distinguished Chair in Human Genetics and a professor of neurology and psychiatry at the David Geffen School of Medicine at UCLA. "Yet when we examined how genes and proteins interact in autistic people's brains, we saw well-defined shared patterns. This common thread could hold the key to pinpointing the disorder's origins."

The research team, led by Geschwind, included scientists from the University of Toronto and King's College London. They compared brain tissue samples obtained after death from 19 autism patients and 17 healthy volunteers. After profiling three brain areas previously linked to autism, the group zeroed in on the cerebral cortex, the most evolved part of the human brain.

The researchers focused on gene expression how a gene's DNA sequence is copied into RNA, which directs the synthesis of cellular molecules called proteins. Each protein is assigned a specific task by the gene to perform in the cell.

By measuring gene-expression levels in the cerebral cortex, the team uncovered consistent differences in how genes in autistic and healthy brains encode information.

"We were surprised to see similar gene expression patterns in most of the autistic brains we studied," said first author Irina Voineagu, a UCLA postdoctoral fellow in neurology. "From a molecular perspective, half of these brains shared a common genetic signature. Given autism's numerous causes, this was an unexpected and exciting finding."

The researchers' next step was to identify the common patterns. To do this, they looked at the cerebral cortex's frontal lobe, which plays a role in judgment, creativity, emotions and speech, and at its temporal lobes, which regulate hearing, language and the processing and interpreting of sounds.

When the scientists compared the frontal and temporal lobes in the healthy brains, they saw that more than 500 genes were expressed at different levels in the two regions.

In the autistic brains, these differences were virtually non-existent.

"In a healthy brain, hundreds of genes behave differently from region to region, and the frontal and temporal lobes are easy to tell apart," Geschwind said. "We didn't see this in the autistic brain. Instead, the frontal lobe closely resembles the temporal lobe. Most of the features that normally distinguish the two regions had disappeared."

Two other clear-cut patterns emerged when the scientists compared the autistic and healthy brains. First, the autistic brain showed a drop in the levels of genes responsible for neuron function and communication. Second, the autistic brain displayed a jump in the levels of genes involved in immune function and inflammatory response.

"Several of the genes that cropped up in these shared patterns were previously linked to autism," said Geschwind. "By demonstrating that this pathology is passed from the genes to the RNA to the cellular proteins, we provide evidence that the common molecular changes in neuron function and communication are a cause, not an effect, of the disease."

The next step will be for the research team to expand its search for the genetic and related causes of autism to other regions of the brain.

Autism is a complex brain disorder that strikes in early childhood. The disease disrupts a child's ability to communicate and develop social relationships and is often accompanied by acute behavioral challenges. In the United States, autism spectrum disorders are diagnosed in one in 110 children and one in 70 boys. Diagnoses have expanded tenfold in the last decade.


'/>"/>

Contact: Elaine Schmidt
eschmidt@mednet.ucla.edu
310-794-2272
University of California - Los Angeles
Source:Eurekalert

Related medicine news :

1. U.S. Rates of Autism, ADHD Continue to Rise: Report
2. Validating preschool programs for children with autism
3. Massachusetts Study Shows Sharp Rise in Early Autism Diagnoses
4. Sporadic mutations identified in children with autism spectrum disorders
5. Fever During Pregnancy, Diabetes and Obesity May Raise Autism Risk
6. Autism Takes an Economic Toll on Moms Job, Income: Study
7. Teen Boys With Autism at Risk of Being Bullied: Study
8. S. Korean Study Suggests Autism Rate May Be Much Higher
9. Winter Conception Tied to Raised Risk for Autism
10. Prevalence of autism in South Korea estimated at 1 in 38 children
11. New study reveals autism prevalence in South Korea estimated to be 2.6 percent or 1 in 38 children
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:10/12/2017)... , ... October 12, 2017 , ... The American College ... to Carol Friedman, PhD, FACMI, during the Opening Session of AMIA’s Annual Symposium in ... , In honor of Morris F. Collen, a pioneer in the field of medical ...
(Date:10/12/2017)... (PRWEB) , ... October 12, 2017 , ... ... drug delivery system that we intend to develop to enable prevention of a ... lead to severe hearing loss, especially in pediatric patients. For cisplatin, hearing loss ...
(Date:10/12/2017)... (PRWEB) , ... October 12, 2017 , ... HMP ... the recipient of a 2017 Folio Magazine Eddie Digital Award for ‘Best B-to-B Healthcare ... City on October 11, 2017. , The annual award competition recognizes editorial and design ...
(Date:10/12/2017)... ... ... On Saturday, October 21, the Health & Wellness Center at Florida Hospital ... for the American Heart Association Heart Walk. Teams of up to 10 people can ... their treadmills moving for 5 hours. Treadmills will start at 7:00 p.m. on Saturday, ...
(Date:10/12/2017)... ... October 12, 2017 , ... Health Literacy Innovations (HLI), creator ... tool, and the Cancer Patient Education Network (CPEN), an independent professional organization that ... new strategic alliance. , As CPEN’s strategic partner, HLI will help support ...
Breaking Medicine News(10 mins):
(Date:9/28/2017)... 28, 2017 Cohen Veterans Bioscience and Early ... of wearable and home sensors for real-time monitoring of ... Foundation, a nonprofit organization focused on disruptive health solutions ... affordable analytical system to record and integrate behavioral, cognitive, ... ...
(Date:9/25/2017)... Sept. 25, 2017   Montrium , an ... solutions, today—from the IQPC Trial Master Files & ... NL)—announced that EastHORN Clinical Services has selected ... and TMF management. EastHORN, a leading European contract ... to increase transparency to enable greater collaboration with ...
(Date:9/22/2017)...  As the latest Obamacare repeal effort moves is ... (R-LA) and Lindsey Graham (R-SC) medical device ... industry is in an odd place.  The industry wants ... tax on medical device sales passed along with the ... increased visits and hospital customers with the funding to ...
Breaking Medicine Technology: