Light Provides Insight
Posted by Rob Ring, PhD, vice president of translational research for Autism Speaks
This week a reporter from Bloomberg News asked me to comment on new research showing how stimulating certain brain cells can spur autism-like symptoms–and how calming these same cells can restore normal behavior. The reporter quoted me as calling the research “revolutionary.” It’s true—for a number of reasons.
We need to study brain activity to better understand and treat social behavior disturbances such as those associated with autism. Researchers do this by seeing what happens when they change what’s happening in the brain. But until now they’ve had only crude methods such as administering chemicals that target many parts of the brain.
To better understand normal and altered brain activity, we need to pinpoint exactly where something is going wrong. It helps to think of brain cells and their connections as microcircuits. Following this analogy, researchers need to be able to test specific microcircuits within the brain.
With this in mind, Karl Deisseroth and his colleagues at Stanford University used genetic engineering to create mice that produce brain chemicals that are activated by light. When activated, these chemicals excite surrounding brain cells. The researchers then used tiny pulses of laser light to produce activity in specific parts of the brain—right down to the level of a few brain cells, or a specific brain circuit.
Using this approach, the researchers found that when they stimulated certain cells in the prefrontal cortex—a part of the brain involved in social behavior—the mice stopped socializing with each other. At the same time, the mice’s brain waves took on a pattern seen in many persons with autism. Then, the researchers used a different light that dampened the activity and calmed the overexcited cells. In response, the mice started socializing again and the autism-like brain waves began to disappear.
The idea here isn’t to control behavior or implant fiber optics in anyone’s brain! What Karl has developed is a way to help us see exactly where something might be going wrong inside a brain and decipher exactly what is happening there.
Importantly this kind of approach may allow us to use lab animals to test new medicines that can help “rebalance” certain brain circuits to ease autism symptoms–and do so with fewer or no side effects.
This is the kind of pioneering research that wins the Nobel Prize. Even more important, we at Autism Speaks want to be supporting research along this promising path toward greater understanding of autism, its prevention and its treatment.