Researchers have figured out how to reverse the symptoms of autism in mice, simply by turning on a gene like a light switch.
Although the technique is a long way off being trialled in humans, the results provide hope that a similar approach could eliminate some of the most frustrating symptoms for people with autism, regardless of their age.
The scientists engineered mice to be born without a gene called Shank3 – which is missing in 1 percent of autism patients.
Scientists have spent decades trying to untangle the maze of genes that contribute to the group of neurodegenerative disorders known as autism, which has become around 10 times more common over the past 40 years.
When Feng and this team engineered mice without Shank3, they found that the brain cells of the mice didn’t grow properly, particularly in a region known as the striatum, which is involved in the brain’s reward system.
These mice also showed characteristic behaviors found in autism spectrum disorders, such as anxiety, compulsive repetition of tasks, and social avoidance.
Once the team switched this gene back on in mice aged between two and 4.5 months they saw some of those behaviors dramatically reverse – the mice started to interact with each other more, and showed less repetitive grooming.
The scientists were able to switch the gene on simply by giving mice the breast cancer drug tamoxifen.
On a cellular level, the researchers saw that there was an increase in the number of dendritic spines – the little branches that neurons use to communicate with each other – in the striatum, suggesting the the gene switch had actually caused the brain to rewire itself.
Although some of the symptoms were eliminated in adult mice, they continued to struggle with anxiety and motor coordination problems.
The team is now trying to better understand when this is, in the hopes of figuring out how to reverse autism symptoms in a broader range of individuals, not only the 1 percent missing Shank3.
A lot of the genetic pathways involved in the development of autism are known to be similar, and it’s exciting to think that we may be able to use a similar approach to help people with autism manage their symptoms.
“Moreover, Feng’s demonstration that restoration of Shank3 function reverses autism symptoms in adult mice suggests that gene therapy may ultimately prove an effective therapy for this disease.”