Scientists found out the relationship between neurotransmitter gamma-aminobutyric acid (GABA) acitvity and autism symptoms, which may identify new ways to diagnose and treat the disorder.
McGovern Intitute for Brain Research postdoc and study lead author Caroline Robertson told MIT that it was the first connection in humans between a neurotransmitter in the brain and an autistic behavioral symptom.
Robertson's team conducted a study, involving a group of participants, in which 50 percent was diagnosed with autism while 50 percent did not have the disorder. The trial participants were asked to accomplish a visual task that needed brain inhibition and anchored on the ability to switch between visual input from the right and left eyes.
The study findings revealeed that those participants with autism switched backed and forth only 50 percent as much as those without autism. In addition, those with autism were considerably less able to curb one image in order to focus on the other mage.
Upon task completion, the research team measured the GABA activity in the participants' brain. Those with higher GABA levels among participants wthout autism better suppressed the non-dominant image. On the other hand, there was no relationship between GABA levels and better task performance in those with autism.
With the results, Robertson explained that in people with autism, GABA was not relating to visual perception, and not indicative of missing GABA or low concentration levels.
In her interview with The Huffington Post, Robertson said that the role of GABA was to limit "runaway excitation" in the brain. This means that the neurotransmitter shutting the brain cells from firing response to signals coming from the external environment.
Robertson also mentioned that it was necessary to filter out signals in the exteernal world that were not relevant to the task at hand and GABA helps in such inhibition. This mechansim involving GABA, led scientists to speculate that decreased AGAB inhibition to execissivey excited nerve cells could be the cause of sensory input hypersensity in people with autism.
According to the lead author, while a lot more work needs to be done, their study findings promises a take off towards improving the diagnosis, treatment, and prevention of autism.
The study findings were published on Dec. 17 in the journal "Current Biology."