Rapamycin reverses autism-like behaviors in mice within hours

A single dose of the immunosuppressant rapamycin reversed key autism-like symptoms in adult mice within two hours, according to a study published in Nature Communications by researchers at the University of California, Los Angeles (UCLA). The rapid effect stunned the scientists, who observed changes in neuronal activity, repetitive behaviors, and sensory hypersensitivity after just one dose Source: ABC.es. The drug, which blocks the mTOR pathway, did not repair structural brain differences but temporarily normalized functional connectivity Source: El Confidencial.

The experiment

Scientists induced a mild inflammatory response in pregnant mice, mimicking a maternal infection linked to higher autism risk in offspring. The adult mice developed chronic inflammation, brain overgrowth, altered connectivity, and autism-like behaviors such as repetitive movements and social deficits. A single dose of rapamycin—used in transplant rejection and cancer treatment—reduced hyperexcitability, seizure susceptibility, and disorganized brain networks within two hours Source: ABC.es.

A conceptual shift

The study challenges the long-held belief that adult brains are structurally fixed after development. "The level of functional normalization achieved in such a short time suggests new mechanisms for future treatments," said lead author Harley Kornblum Source: ABC.es. However, rapamycin is toxic with prolonged use and loses efficacy quickly, so it is not a clinical therapy Source: El Confidencial. The findings open avenues for therapies targeting brain circuits rather than structure.