Autism anxiety may in part stem from an abnormal sense of touch
Dialing down touch over-reactivity in Autism Spectrum Disorders improves some behavioural symptoms in mice
Lauren Orefice knew when one of her lab mice bit her that she was onto something big.
The genetics researcher from Harvard Medical School had been working with lab mice for most of her career, so she knew how to handle them so they wouldn't bite.
But these weren't normal mice. They were "genetic models," designed with a mutation to one of the many Autism Spectrum Disorder (ASD) genes she'd been investigating.
When the mouse, which had a mutation in an Autism Spectrum Disorder (ASD) gene — not in its brain, but in its touch neurons, Orefice realized that contrary to what scientists have thought for years, autism may actually stem in part from an abnormal sense of touch rather than how their brain is wired.
Abnormal sense of touch leads to impaired social functions
"What was even more surprising was their general behaviour towards the investigators, but also to other animals. The mice developed pretty profound anxiety-like behaviours, as well as social impairments when they were interacting with other mice," said Orefice
It's not that abnormal brain wiring leads to over-reactivity to touch and social impairments in those with ASD, but that a difference in their sense of touch leads to abnormal brain development.
They saw "pretty striking abnormalities" in the parts of the brain that processes touch signals, as well as in the region that helps regulate social behaviours and anxiety in rodents.
She also discovered that if she gave the young mice that had an over-reactivity to touch a drug compound — only available for research purposes — that reduces the sensory flow from touch neurons to the brain, she could improve their anxiety and social impairments.