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Office of Neuroscience Research > WUSTL Neuroscience News > Pinpointing autism’s faulty circuitry

Pinpointing autism’s faulty circuitry

From Cosmos Magazine... 

People diagnosed as residing on the autism spectrum suffer from a fuzzy kind of disorder. It can’t be identified by a brain scan. Not so long ago it wasn’t even thought to have a physiological basis; it was blamed on bad parenting.

Those who fit the diagnosis range from highly intelligent and articulate to non-verbal and intellectually disabled. A third suffer from seizures. They are four times more likely to have gastrointestinal problems than their peers. They may have movement difficulties, or be unusually sensitive to noise.

What unites all people with autism spectrum disorder (ASD) is a problem with their sociability, but what exactly in the brain has gone awry?

Now, by following a hunch and using genetic tools to finely dissect the circuity of the brain, a team led by Matthew Anderson at Harvard Medical School has traced what appears to be a sociability circuit in mice.

Surprisingly the circuit does not lie in the prefrontal cortex, the part of the brain associated with communication. Rather, it is in a tiny zone at the top of the brain’s most primitive region, the brain stem. Known as the ventral tegmental area (VTA), it is well-known for its role in rewarding behaviours such as eating, having sex and taking drugs. Now it appears it may reward social behaviour as well.

Using a molecular chemogenetic switch in mice, Anderson’s team was able to turn this circuit off and on, generating animals that were asocial or hyper-social.

The findings, reported in Nature in March, may finally help open the door to new treatments for autism. “Finding a circuit that is linked to ASD is essential for developing therapeutic strategies,” says Joseph Dougherty, who studies mouse models of autism at Washington University in St. Louis.

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