Landmark Study Identifies Key Brain Difference In Autism

Neuroscientists at Harvard and MIT have identified, for the first time, a link between the activity of the neurotransmitter GABA and symptoms of autism — a finding that may pave the way for new methods of treating and diagnosing the disorder.

“This is the first connection in humans between a neurotransmitter in the brain and an autistic behavioral symptom,” Caroline Robertson, a postdoc at MIT’s McGovern Institute for Brain Research and the study’s lead author, said in a statement.

The role of the GABA neurotransmitter is to inhibit brain cells from firing in response to signals received from the external environment — or as Robertson told The Huffington Post, to curb “runaway excitation” in the brain.

“GABA is responsible for signaling that neurons should turn off, or stop firing,” Robertson told HuffPost. “It tends to come into play … when information is being transmitted and it needs to be shut down or filtered out.”

Scientists have speculated that a lack of GABA inhibition to overexcited neurons could be the underlying cause of the hypersensitivity to sensory input seen in individuals with autism.

“It’s necessary to filter out signals in the external world that aren’t relevant to the task at hand,” Robertson said. “GABA helps us in this kind of inhibition.”

Hypersensitivity to one’s external environment makes it difficult for individuals with autism to tune out distracting sounds and sensations, and can make them feel overwhelmed in loud or highly stimulating situations. For instance, some children with autism tend to be easily distracted by sensations like the feel of an itchy sweater or by ambient noise in the background of a conversation. Hypersensitivity also plays a role in the main symptoms of the disorder, including impaired social skills, communication difficulties and repetitive behaviors.

So, it may be that when GABA —> Read More