A newly-published study concluded that a mutation of the disease-causing gene in the autism-related disorder Timothy syndrome reverses a key neurodevelopment process, causing shrinkage rather than growth of the brain wiring needed for the development of neural circuits upon which cognition is based.
The finding may offer an explanation for the mechanisms underlying intellectual disability and other brain disorders.
“In addition to the implications for autism, what’s really exciting is that we now have a way to get at the core mechanisms tying genes and environmental influences to development and disease processes in the brain,” said Ricardo Dolmetsch, Ph.D., senior director of molecular networks at the Allen Institute for Brain Science. “Imagine what we can learn if we do this hundreds and hundreds of times for many different human genetic variations in a large-scale, systematic way. That’s what we are doing now.”
Dr. Dolmetsch led the team of colleagues at Stanford University that published the finding yesterday, in a Nature Neuroscience study. The study found that the dendrites of cells with the mutation found in Timothy’s syndrome retract in response to neural activity, rather than stretch or expand as happens in normal brain development. The study also identified a previously unknown mode of signaling to uncover the chemical pathway that causes the dendritic retraction.
As the same gene has been implicated in bipolar disorder and schizophrenia, the team also concluded the study finding may have wide-reaching implications for neuroscience, since impaired dendrite formation is common to several neurodevelopmental disorders.
Dr. Dolmetsch leads the Molecular Networks program, one of three major new initiatives announced by the Allen Institute last March. In addition to identifying the molecular and environmental rules that shape how the brain is built, the program is designed to create new research tools and data sets to be shared publicly with the global research community.
The Allen Institute is named for Paul G. Allen, who co-founded Microsoft with Bill Gates and has expanded his business activities beyond technology to real estate investment, sports franchise ownership, and philanthropy. Last year, Mr. Allen committed an additional $300 million for the first four years of a 10-year plan to further propel and expand the Institute’s scientific programs. He has committed a total $500 million to the institute since joining his wife Jody Allen in co-founding it in 2003 with $100 million in seed funding.
At Stanford, Dr. Dolmetsch’s lab studies the underlying neurobiology of autism and other neurodevelopmental disorders—especially how electrical activity and calcium signals control the development of the brain, and how that development is altered in children with autism spectrum disorders.