A newly published brain-tissue study suggests that children affected by autism have a surplus of synapses, or connections between brain cells. The excess is due to a slowdown in the normal pruning process that occurs during brain development, the researchers say.
The study team also found that the medication rapamycin both restores normal synaptic pruning and reduces autism-like behaviors in a mouse model of autism. They propose that someday a similar medication might be used to treat autism after a child – or even adult – has been diagnosed.
The report, by neuroscientists at Columbia University Medical Center, appears in the journal Neuron.
Autism Speaks is currently funding several studies on rapamycin. It is also supporting a treatment study using a medication with a very similar action for treatment of autism associated with tuberous sclerosis complex (TSC). This rare syndrome often, but not always, involves autism. Indeed, the laboratory mice used in the new Columbia study were developed as an animal model of this syndrome.
“There are many unknowns in translating research from mice to humans,” comments Paul Wang, Autism Speaks senior vice president and head of medical research. “But the data from mice suggest that such medicines could have a positive effect on behavior and cognition in patients with TSC. The findings of this newest study might also be relevant to a subset of other patients with autism.” Dr. Wang was not involved in the new Columbia study.
The insights from the new study also underscore the vital importance of post-mortem brain donations in advancing research on autism treatments, Dr. Wang adds.