Scientists discover clues to altered brain wiring in autism

November 15, 2016
Credit: CC0 Public Domain

Autism is an agonizing puzzle, a complex mixture of genetic and environmental factors. One piece of this puzzle that has emerged in recent years is a biochemical cascade called the mTOR pathway that regulates growth in the developing brain. A mutation in one of the genes that controls this pathway, PTEN (also known as phosphatase and tensin homolog), can cause a particular form of autism called macrocephaly/autism syndrome.

Using an animal model of this syndrome, scientists from the Florida campus of The Scripps Research Institute (TSRI) have discovered that mutations in PTEN affect the assembly of connections between two brain areas important for the processing of social cues: the , an area of the brain associated with complex cognitive processes such as moderating social behavior, and the amygdala, which plays a role in emotional processing.

"When PTEN is mutated, we find that neurons that project from the prefrontal cortex to the amygdala are overgrown and make more synapses," said TSRI Associate Professor Damon Page. "In this case, more synapses are not necessary a good thing because this contributes to abnormal activity in the amygdala and deficits in social behavior."

The study was published on November 15 by the journal Nature Communications. The study also showed that targeting the activity of the mTOR pathway shortly after birth, a time when neurons are forming connections between these , can block the emergence of abnormal amygdala activity and social behavioral deficits. Likewise, reducing activity neurons that project between these areas in adulthood can also reverse these symptoms.

"Given that the functional connectivity between the prefrontal cortex and amygdala is largely conserved between mice and humans," said TSRI Graduate Student Wen-Chin Huang, the first author of the study, "we anticipate the therapeutic strategies suggested here may be relevant for individuals on the spectrum."

Although caution is warranted in extrapolating findings from animal models to humans, these findings have implications for individualized approaches to treating autism. "Even within individuals exposed to the same risk factor, different strategies may be appropriate to treat the symptoms of autism in early development versus maturity," said Page.

Explore further: Scientists identify key receptor as potential target for treatment of autism

More information: Nature Communications, "Hyperconnectivity of Prefrontal Cortex to Amygdala Projections in a Mouse Model of Macrocephaly/Autism Syndrome" (2016)

Related Stories

Scientists identify key receptor as potential target for treatment of autism

September 30, 2015
Scientists from the Florida campus of The Scripps Research Institute (TSRI) have uncovered a significant—and potentially treatable—relationship between a chemical that helps transmit signals in the brain and genetic mutations ...

Scientists find mechanism for altered pattern of brain growth in autism spectrum disorder

July 15, 2015
As early as 1943, when autism was first described by psychiatrist Leo Kanner, reports were made that some, but not all, children with autism spectrum disorder have relatively enlarged heads. But even today, more than half ...

Scientists find connection between gene mutation, key symptoms of autism

April 25, 2014
Scientists have known that abnormal brain growth is associated with autism spectrum disorder. However, the relationship between the two has not been well understood.

Mouse model points to potential drug target for increasing social interaction in autism

September 8, 2016
A study of a new mouse model identifies a drug target that has the potential to increase social interaction in individuals with some forms of autism spectrum disorder (ASD), according to researchers in the Perelman School ...

Study shows less aggressive behavior toward strangers in autism spectrum disorder model

February 25, 2015
While aggression toward caregivers and peers is a challenge faced by many individuals and families dealing with autism, there has been much speculation in the media over the possibility of generally heightened aggression ...

Researchers temporarily turn off brain area to better understand function

July 21, 2016
Capitalizing on experimental genetic techniques, researchers at the California National Primate Research Center, or CNPRC, at the University of California, Davis, have demonstrated that temporarily turning off an area of ...

Recommended for you

Late-breaking mutations may play an important role in autism

July 17, 2017
A study of nearly 6,000 families, combining three genetic sequencing technologies, finds that mutations that occur after conception play an important role in autism. A team led by investigators at Boston Children's Hospital ...

Females with autism show greater difficulty with day-to-day tasks than male counterparts

July 14, 2017
Women and girls with autism may face greater challenges with real world planning, organization and other daily living skills, according to a study published in the journal Autism Research.

Researchers investigate possible link between carnitine deficiency and autism

July 13, 2017
Researchers are always looking for new clues to the causes of autism, with special emphasis on prevention or treatment. At Baylor College of Medicine, Dr. Arthur Beaudet has been following clinical and genetic clues in patients ...

How children look at mom's face is influenced by genetic factors and altered in autism

July 12, 2017
New research has uncovered compelling evidence that genetics plays a major role in how children look at the world and whether they have a preference for gazing at people's eyes and faces or at objects.

Oxytocin improves social abilities in some kids with autism, study finds

July 10, 2017
Children with autism showed improved social behavior when treated with oxytocin, a hormone linked to social abilities, according to a new study by researchers at the Stanford University School of Medicine. Children with low ...

Possible early diagnosis of autism spectrum disorder

June 29, 2017
Measuring a set of proteins in the blood may enable earlier diagnosis of autism spectrum disorder (ASD), according to a study from the Peter O'Donnell Jr. Brain Institute at UT Southwestern Medical Center.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.