Scientists say switching on a gene linked to autism spectrum disorder could reverse some of the illnesses’ symptoms — in mice.
A new study suggests the activation of a gene called Shank3, which is sometimes absent in people with autism but is important for coding proteins that help transport information across the brain, can help eliminate certain behaviors in mice that are similar to those found in humans with autism, like social avoidance and repetitive activity. The research was published in the journal Nature in February.
Since very little is known about the causes of autism, finding a connection between Shank3 and autism may be particularly significant. While only about 1 percent of people with an autism disorder lack the Shank3 gene, understanding the gene’s purpose could give researchers clues about how to treat the disorder. Scientists have already found that Shank3 is important for basic brain functions, like helping information flow across the brain’s synaptic highways from one neuron to the next. The brain’s intricate web of these neurons gives rise to complex skills, like the use of language to communicate and the ability to interact in social situations.
Using gene-editing technology, scientists at Massachusetts Institute of Technology tested whether turning off — and then turning back on — the Shank3 gene would have a noticeable effect on autism-like symptoms. To begin, they deleted the Shank3 gene in mice embryos using a special enzyme that can splice out parts of the genetic code. Shortly after the mutated mice were born, the scientists noticed they compulsively groomed themselves and were less active than the control group. Once the Shank3-free mice reached adulthood, scientists flicked their Shank3 genes back on by administering a dose of tamoxifen. The mice grew more social and showed noticeably fewer repetitive behaviors.
Not all the symptoms went away: the adult mice were still anxious and their motor skills didn’t improve. But when the scientists tried another method — turning on the gene just 20 days after the mice were born — the younger mice had less anxiety and displayed
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