(dailyRx News) Serotonin is a chemical in the brain that carries signals between nerve cells. There are increased serotonin levels in the bloodstream of those with autism - but, until recently, nobody knew why.
The researchers believe that the high serotonin levels are caused by a single gene that regulates the serotonin transporter (SERT), a membrane protein that regulates serotonin in the nervous system. They have duplicated symptoms of autism in mice, including the elevated serotonin levels.
"Remarkably, these mice show changes in social behavior and communication from early life that may parallel aspects of ASD,” said Jeremy Veenstra-VanderWeele, Ph.D., assistant professor of Psychiatry, Pediatrics and Pharmacology at Vanderbilt Kennedy Center.
In 2005, another research team identified genetic variations in children with autism that disrupted SERT behavior. This new study has produced similar disruptions in SERT behavior in mice, and has related it to the same gene in mice.
The research suggests that the gene mutation causes SERT to go into ‘overdrive,’ causing serotonin to be removed from the nervous system and collected in platelets in the bloodstream. The lower serotonin levels in the brain then cause many symptoms related to autism.
The team stresses that a mouse model cannot completely explain the human condition of autism. They also note that autism is not caused by a single genetic variation - but a complex web of genes and environmental factors.
However, the research may lead to a greater understanding of the disorder and possible treatments.
The study was published online March 19th, 2012, in the journal Proceedings of the National Academy of Sciences and was funded by the National Institutes of Health, the advocacy organization Autism Speaks, and the American Academy of Child and Adolescent Psychiatry.