A new study indicates that imbalances in GABA brain cell receptor activity may be a cause of autism.
The study is the first in which researchers have verified a connection between autism symptoms and brain levels of gamma-aminobutyric acid (GABA). GABA is the neurotransmitter responsible for calming.
"Often, people with autism have trouble filtering irrelevant sensory information, and it’s long been thought this might have something to do with inhibition in the brain," Caroline Robertson, study leader and researcher with the Harvard Society of Fellows, said.
Although animals have been the subject of prior GABA studies, the new study -- funded by a Milton Fund Grant from Harvard University, a Seed Grant from the Simons Center for the Social Brain at the Massachusetts Institute of Technology (MIT) and an MIT-Mass General Hospital Grand Challenge Award -- was the first to use humans. Forty-two participants, 21 of them autistic, participated.
"(The study) shows that the link between GABA and the ability to suppress competing images is completely absent in autism," Robertson said. "It also suggests a disruption in inhibitory signaling in the autistic brain."
Robertson plans to conduct further research.
"We want to see more research bridging the gap between animal and human research on autistic neurobiology, with the aim of developing new medications to ease symptoms in people disabled by the condition," she said.
