A molecule that promotes brain development could serve as a possible treatment for Rett syndrome, the most common form of autism in girls, according to researchers at MIT's Picower Institute for Learning and Memory and the Whitehead Institute for Biomedical Research.
The researchers found that injecting the molecule into mice that have an equivalent of Rett syndrome helped the animals' faulty brain cells develop normally and reversed some of the disorder's symptoms.
The work, reported in the Feb. 10 online edition of the Proceedings of the National Academy of Sciences ( PNAS ), is expected to lead to new human clinical trials for a derivative of growth factor-1 (IGF-1), currently used to treat growth disorders and control blood glucose. The MIT study indicates that IGF-1 could potentially lessen the severity of symptoms of Rett syndrome.
"We demonstrate that a major underlying mechanism behind Rett syndrome in mice is that synapses in the brain remain immature and show persistent, abnormal plasticity into adulthood," said Daniela Tropea, a postdoctoral fellow at the Picower Institute and lead author of the study. "We also propose that a therapeutic based on this mechanism would be directly applicable to humans."
Injecting mice with a peptide fragment of IGF-1, used by the brain for neuronal and synaptic development, reverses a large number of symptoms of mice genetically engineered to display Rett syndrome-like symptoms.
"IGF-1 is critical for brain development. It activates molecules within neurons that make synapses mature," said study co-author Mriganka Sur, the Newton Professor of Neuroscience at the Picower Institute and head of the MIT Department of Brain and Cognitive Sciences. "This is a mechanism-based therapeutic for Rett syndrome. It is possible that this or similar therapeutics would apply to other forms of autism, which also have as their basis a persistent immaturity of synapses."
HELPING NERVE CELLS MATURE
Rett syndrome, an inherited neurological disorder, causes loss of speech, reduced head size, breathing and heart abnormalities and autism-like symptoms in one out of 10,000 girls.