Serotonin plays role in many autism cases, studies confirm

Feb 24, 2011
In research studies of autism spectrum disorder, social interaction behaviors of mice were measured by placing them in a three-chamber social interaction test and positioning a "stranger" mouse in one of the chambers. Mice treated with a medication that mimics the effects of serotonin spent more time in the chamber with the stranger mouse than untreated mice and more time sniffing the stranger. Credit: UT Health Science Center San Antonio

Mouse models are yielding important clues about the nature of autism spectrum disorders, which impact an estimated one in 110 children in the U.S. In labs at the UT Health Science Center San Antonio, researchers are studying strains of mice that inherently mimic the repetitive and socially impaired behaviors present in these disorders.

Georgianna Gould, Ph.D., research assistant professor of physiology in the Graduate School of Biomedical Sciences, is eyeing the role that serotonin plays in .

Serotonin is known for giving a sense of well-being and happiness. It is a neurotransmitter, a chemical that acts like a radio tower in the brain conveying signals among cells called neurons. Thirty percent of autism cases may have a serotonin component.

In a recent paper in the Journal of Neurochemistry, Dr. Gould and colleagues showed that a medication called buspirone improved the social behaviors of mice. Buspirone is approved by the U.S. for use in adults as an anti-anxiety and antidepressant adjuvant medication.

Some genetic variations result in diminished transmission of serotonin between neurons. Buspirone increased transmission by partially mimicking the effects of serotonin at cellular sites called receptors.

Reactions to newly encountered mouse

behaviors of the mice were measured by placing them in a three-chamber social interaction test and positioning a "stranger" mouse in one of the chambers. Buspirone-treated mice spent more time in the chamber with the stranger mouse than untreated mice and more time sniffing the stranger.

"No is completely characteristic of humans, and we're far from saying that buspirone is a treatment for behaviors of autistic people," Dr. Gould said. "But this does offer further proof that serotonin is involved in a significant proportion of autism cases."

Support from the San Antonio Area Foundation made the project possible. Co-authors of the journal article are Julie Hensler, Ph.D., and Teri Frosto Burke, M.S., of the pharmacology department at the Health Science Center; Lynette Daws, Ph.D., of the university's physiology department in whose lab the work was conducted; and Robert Benno, Ph.D., and Emmanuel Onaivi, Ph.D., of the biology department at William Paterson University in Wayne, N.J.

2nd serotonin-related avenue

Dr. Gould now plans to study the impact of a diet rich in the amino acid, tryptophan, on the social behavior of the mice. Tryptophan is a biochemical precursor of serotonin, which means it is converted into during the metabolic process. Foods such as turkey are rich in tryptophan.

"We are going to supplement the diet of mice with tryptophan to see if behavior improves, and also reduce it to see if behavior worsens," Dr. Gould said. The future study of tryptophan is funded by the Morrison Trust, a San Antonio trust that lists nutrition as one of its topics of interest.

Explore further: Why your nose can be a pathfinder

Provided by University of Texas Health Science Center at San Antonio

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User comments : 6

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petrossa
5 / 5 (2) Feb 24, 2011
I'm sure all known neurotransmitters to man play a role in any mental issue. I strongly doubt the validity or the use of this 'study'.

Autism is caused by genetically regulated formation of the Corpus Callosum. The resemblance between Agenesis of the CC and Autism is to striking. The hemispheres connect in a different way causing a developmental difference to the norm due to over/under stimulation due to the 'faulty wiring'.

Squirrel
3 / 5 (1) Feb 24, 2011
No mouse model exists of autism, full stop. The atypical cognition of those with autism concern language, ability to understand minds, and impaired social interactions such as mutual play. No mouse speaks, has awareness of other's intents nor shares play activities. To write "No animal model is completely characteristic of humans" is grossly dishonest. The word "completely" is a trick that misleading implies that is an element of comparison whereas in fact no connection of any kind exists.

This research is more informative of how animal researcher's are gaming funding organizations than autism.
DrSki
not rated yet Feb 27, 2011
Multiple mechanisms exist for what is now a too often inclusive diagnosis of "AUTISM". A portion of these cases don't fit the criteria, and therefore include those chemical neurotransmitter imbalances that have a variety of presentations clinically. Treating these human patients with CNS transmitter modifying agents DOES result in improvement/"cure" of the (sic)"autism". The patients who respond no longer have 'autism' - without any structural changes taking place in the brain. It's unfortunate that the medical community doesn't insist on keeping the definitions narrow enough in this disease, or ADD/ADHD, or Alzheimers dementia (which has been usurped to include vascular dementia, diabetic dementia, hypertensive dementia - there is even overlap in these).
petrossa
not rated yet Feb 27, 2011
Good observation. Anything from ADHD to having a bad hair day is now diagnosed as some form of autism. Wise decision to make the syndrome even more obtuse in DSM V. /sarc
JOHNSPEAKS
not rated yet Mar 01, 2011
As a proud non professional I observed and then documented many cases of -Autistic- human beings being helped by serotonin based -Kindness- in their daily lives? We saw this behavior in a mental health rehabilitation facility in northern new jersey many years ago? Since I am not a professional nobody would look at years of full time documented facts similar to -Lorenzo's Oil- story of hope by non professionals? When you have inbreeding by professionals over time the results become suspect???
petrossa
not rated yet Mar 01, 2011
As an autist myself and taking SSRI's i can positively confirm it alleviates a bit the anxiety. For the rest it doesn't do squat. It can't because in REAL autism (not some 'hey he's ascocial and behaves weird, let's call him autist) the brain is completely differently wired. There's no way no how you are going to rectify that by means.

All one can do is combat some of the less pleasant symptoms.

Says a non-professional nobody but a personal experienced one. Beats non professional observers anytime.

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