In a recent study published in the journal Current Biology, Harvard scientists have discovered a link between a specific neurotransmitter with behavior associated with Autism. By use of a visual test that elicits different reactions in brains with Autism and brains without Autism, the Harvard Society of Fellows was able to show that the differences were associated with a breakdown in the signaling pathway used by GABA, one of the brain’s main inhibitory neurotransmitters.
Caroline Robertson, a junior fellow, details the important discovery in Autism research:
“This is the first time, in humans, that a neurotransmitter in the brain has been linked to autistic behavior – full stop. This theory that the GABA signaling pathways plays a role in autism has been shown in animal models, but until now we never had evidence for it actually causing autistic differences in humans.”
Robertson said the finding offers insight into the disorder and the role neurotransmitters play in it. The discovery also suggests that similar visual tests could be used to screen younger children for autism, which would allow parents and clinicians to intervene sooner.
The team utilized what is called a binocular rivalry test. An easily replicable test, it produces consistent results in people with and without Autism. Robertson describes the test:
“The end result is that one image is just suppressed entirely from visual awareness for a short period. So if I show you a picture of a horse and an apple, the horse will entirely go away, and you will just see the apple. Eventually, though, the neurons that are forcing that inhibitory signal get tired, and it will switch until you only see the horse. As the process repeats, the two images will rock back and forth. Where the average person might rock back and forth between the two images every three seconds, an autistic person might take twice as long.”
Robertson cautions that understanding the signaling pathway for GABA will not be a direct cure for autism. Excited about the recent study, she explains how there are many molecule in the brain that may be associated with Autism in some form, and there is more research to be done.
“We’re not done screening the autistic brain for other possible pathways that may play a role. But this is one, an we feel good about this one.”