Nav: Home

Zebrafish study provides new insights into autism spectrum disorder research

January 24, 2018

CORVALLIS, Ore. - Exposure to a compound used to treat migraines and seizures causes characteristics associated with autism, groundbreaking research with zebrafish has demonstrated.

The study conducted by Oregon State University and Wenzhou Medical University showed valproic acid exposure resulted in phenotypes and behaviors consistent with autism spectrum disorder, or ASD, and validated zebrafish as a model for studying ASD and its causes.

"The main thing we want to emphasize is the usefulness of this model," said co-author Courtney Roper, a postdoctoral fellow in OSU's College of Agricultural Sciences. "We can very quickly look at genetic and environmental factors associated with autism that are very difficult to understand in humans. The ease and speed of the genetic analysis in this model make it very attractive compared to a rodent model."

Autism spectrum disorder consists of five related neurodevelopmental disorders characterized by pervasive impairments in social interactions, deficits in verbal and nonverbal communication, repetitive patterns of behaviors and unusual sensitivity to sensory stimulation.

All of the factors behind autism are not known, but the etiology is known to have both genetic and environmental components, including prenatal exposure to two drugs: thalidomide, a sedative associated with severe birth defects, and valproic acid.

Autism diagnoses have been on the rise since the 1990s. According to the Centers for Disease Control, about one child in 68 will be identified with autism spectrum disorder.

ASD strikes all racial, ethnic and socioeconomic groups but is about 4.5 times more common among boys (1 in 42) than girls (1 in 189).

Zebrafish are a small freshwater species that go from a cell to a swimming fish in about five days. They reproduce rapidly and are particularly useful for studying the development and genetics of vertebrates, including the effects of environmental contaminants and pharmaceuticals on early embryonic development.

Zebrafish share a remarkable similarity to humans at the molecular, genetic and cellular levels, meaning many zebrafish findings are immediately relevant to humans. Embryonic zebrafish are of special interest because they develop quickly, are transparent and can be easily maintained in small amounts of water.

The OSU findings showed that treating zebrafish embryos with valproic acid, or VPA, starting eight hours after fertilization led to a significant increase in the ASD macrocephalic phenotype - i.e., an enlarged head.

It also caused hyperactivity of movement behaviors in embryos and larvae, and a tendency toward ASD-like larval social behaviors.

"In addition to the ASD-like characteristics, we observed an overgrowth of mature newborn neurons and neural stem cells in the developing brain after VPA exposure," Roper said. "Next, now that we have models for behavior established, is to start looking at the genetic and environmental interactions, examining some of the potential factors that might be driving autism in humans."
-end-
Findings were recently published in Neurotoxicology and Teratology. The National Natural Science Foundation of China supported this research, as did Wenzhou Medical University.

Oregon State University

Related Autism Articles:

Genes, ozone, and autism
Exposure to ozone in the environment puts individuals with high levels of genetic variation at an even higher risk for developing autism than would be expected just by adding the two risk factors together, a new analysis shows.
A blood test for autism
An algorithm based on levels of metabolites found in a blood sample can accurately predict whether a child is on the autism spectrum of disorder (ASD), based upon a recent study.
New form of autism found
Autism spectrum disorders (ASD) affect around one percent of the world's population and are characterized by a range of difficulties in social interaction and communication.
Autism Speaks MSSNG study expands understanding of autism's complex genetics
A new study from Autism Speaks' MSSNG program expands understanding of autism's complex causes and may hold clues for the future development of targeted treatments.
Paths to Autism: One or Many?
A new report in Biological Psychiatry reports that brain alterations in infants at risk for autism may be widespread and affect multiple systems, in contrast to the widely held assumption of impairment specifically in social brain networks.
Raising a child with autism
Humans are resilient, even facing the toughest of life's challenges.
Explaining autism
Recognizing a need to better understand the biology that produces Autism Spectrum Disorder (ASD) symptoms, scientists at Duke-NUS Medical School (Duke-NUS) and the National Neuroscience Institute (NNI), Singapore, have teamed up and identified a novel mechanism that potentially links abnormal brain development to the cause of ASDs.
Autism breakthrough
Using a visual test that is known to prompt different reactions in autistic and normal brains, Harvard researchers have shown that those differences were associated with a breakdown in the signaling pathway used by GABA, one of the brain's chief inhibitory neurotransmitters.
New options for treating autism
The release of oxytocin leads to an increase in the production of anandamide, which causes mice to display a preference for interacting socially.
The Autism Science Foundation launches the Autism Sisters Project
The Autism Science Foundation, a not-for-profit organization dedicated to supporting and funding autism research, today announced the launch of the Autism Sisters Project, a new initiative that will give unaffected sisters of individuals with autism the opportunity to take an active role in accelerating research into the 'Female Protective Effect.'

Related Autism Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Don't Fear Math
Why do many of us hate, even fear math? Why are we convinced we're bad at it? This hour, TED speakers explore the myths we tell ourselves and how changing our approach can unlock the beauty of math. Guests include budgeting specialist Phylecia Jones, mathematician and educator Dan Finkel, math teacher Eddie Woo, educator Masha Gershman, and radio personality and eternal math nerd Adam Spencer.
Now Playing: Science for the People

#517 Life in Plastic, Not Fantastic
Our modern lives run on plastic. It's in the computers and phones we use. It's in our clothing, it wraps our food. It surrounds us every day, and when we throw it out, it's devastating for the environment. This week we air a live show we recorded at the 2019 Advancement of Science meeting in Washington, D.C., where Bethany Brookshire sat down with three plastics researchers - Christina Simkanin, Chelsea Rochman, and Jennifer Provencher - and a live audience to discuss plastics in our oceans. Where they are, where they are going, and what they carry with them. Related links:...