A study conducted by researchers at the University of California, Los Angeles (UCLA) suggests that rapamycin, an antibiotic approved by the FDA, may temporarily reverse autism symptoms in adult mice. The findings, published in Nature Communications, indicate that a single dose of the drug can lead to a significant decrease in repetitive behaviors.
In the research, adult mice exhibiting autism-like behaviors were administered a solution containing five milligrams of rapamycin. Within two hours, the rodents displayed fewer repetitive actions, such as excessive grooming or circling. This effect persisted for approximately 72 hours before the behaviors returned to their previous levels.
Dr. Harley Kornblum, a neuroscientist who led the study, noted that the rapid and substantial functional normalization observed suggests novel mechanisms for potential treatments. He added that the results imply adult brains might be more adaptable than previously assumed, even with underlying developmental structural changes.
Rapamycin, discovered in the 1970s, is primarily used to prevent organ transplant rejection. It has also garnered attention from biohackers for its potential to slow aging, with some studies showing it can extend the lifespan of mice. However, other human studies have noted potential drawbacks, including a blunting effect on exercise benefits.
The UCLA researchers suggest that rapamycin's rapid effect in the study indicates it may not rewire the brain but rather calm dysfunctional neurons contributing to autism-associated symptoms. Tests showed a reduction in abnormal brain activity in mice treated with the drug. However, after five weeks of daily injections, the drug's effect subsided.
Autism spectrum disorder, characterized by difficulties in social situations, repetitive behaviors, and challenges with varying routines, affects an estimated one in 31 children and five million adults in the United States. Current treatments typically involve behavioral therapies and sometimes medications for co-occurring conditions like anxiety or depression. There is no known cure for autism.
The researchers cautioned that their study was not conducted in humans and that the impact of rapamycin on individuals with autism remains unclear. They emphasized that further testing is necessary before the drug could be considered a viable treatment for humans. The study did not identify rapamycin as a treatment for human autism symptoms due to its temporary effects and the potential for toxicity with repeated doses. Instead, the drug's observed effects are intended to reveal new therapeutic targets for future treatments.
Potential side effects of rapamycin include high blood pressure, kidney injury, infections, and swelling. In more serious cases, it has been linked to blood clotting and lung problems. Biohacker Bryan Johnson, who previously used rapamycin for anti-aging purposes, ceased its use, citing that the risks outweighed the benefits and potentially contributed to skin infections and increased heart rate.