Molecular Difference in Autistic Brains Discovered

Scientists have discovered a molecular difference in the brains of autistic people compared to their neurotypical counterparts.

Autism is a neurodevelopmental condition associated with behavioral differences including difficulties with social interaction, restrictive or intense interests, and repetitive movements or speech. But it’s not clear what makes autistic brains different.

Now, a new study in The American journal of Psychiatry has found that brains of autistic people have fewer of a specific kind of receptor for glutamate, the most common excitatory neurotransmitter in the brain. The reduced availability of these receptors may be associated with various characteristics linked to autism.

“we have found this really crucial, never-before-understood difference in autism that is meaningful, has implications for intervention, and can help us understand autism in a more concrete way than we ever have before,” says James McPartland, a professor of child psychiatry and psychology in the Child Study Center at Yale School of Medicine (YSM) and the study’s co-principal investigator.

Neurons in the brain communicate with one another using electrical signals and chemical messengers called neurotransmitters. When an electrical current propagates through a neuron, it prompts the release of neurotransmitters that relay a signal to other neurons. This signaling in the brain can be either excitatory or inhibitory. Excitatory signaling primarily triggers the release of the neurotransmitter glutamate, and it acts as a green light telling other neurons to fire.Inhibitory signaling, on the other hand, acts as a brake that suppresses activity.

The brain needs a precise balance of these two types of signaling in order to function properly. One of the leading hypotheses on the underlying causes of autism is an imbalance of excitatory and inhibitory signaling in the brain. Researchers propose the involvement of this central mechanism might explain the wide range of differences observed among autistic individuals.

Based on this hypothesis, the researchers used magnetic resonance imaging (MRI) and positron emission tomography (PET) to look for differences in the brains of 16 autistic adults and 16 people considered neurotypical. MRI