By Marion Davis
PROVIDENCE – Researchers at Brown University and Stanford University have launched a $14.9 million project geared to developing new brain micro-implants that can both sense the brain’s electrical signals and deliver optogenetic lightpulses to neural tissue.
The project, funded by a two-year Defense Advanced Research Projects Agency (DARPA) grant, is being led by Krishna Shenoy, a Stanford researcher, and Arto Nurmikko, a professor of electrical engineering and physics at Brown.
It also includes several other Stanford and Brown researchers – including John Donoghue and colleagues in his BrainGate lab – as well as faculty at the University of California-San Francisco and University College London, 10 people altogether.
The team includes experts in neuroscience, neurology and psychiatry to semiconductors, optoelectronics, statistical signal processing, machine learning and brain modeling.
The project is called REPAIR (Reorganization and Plasticity to Accelerate Injury Recovery), and DARPA has provided an option to expand funding to $28.8 million over four years.
“This program is about conducting the fundamental neuroscience and developing the neurotechnology to ultimately enable an entirely new class of brain injury therapeutics,” said Shenoy, an associate professor of electrical engineering and of bioengineering at Stanford.
“Using new tools like optogenetics,” he added, “which enables us to interact with, and even temporarily turn off, active brain circuits in animals with pulses of light, our team can harmlessly simulate injuries and therefore learn more about how the brain responds when an injury occurs. The understanding of brain function that we create will help pave the way to new approaches to mitigating the effects of injury.”
The ultimate goal, said Nurmikko, is to achieve “a clinically useful, two-way communication link with the brain” to understand how the brain responds to injuries and develop therapies to help people who have suffered such injuries.
About 1.7 million people experience traumatic brain injuries each year in the United States, including many in the military service, according to the Centers for Disease Control and Prevention.
The technologies that REPAIR will use allow researchers to genetically engineer specific types of cells in brain circuits that will turn on or off in response to pulses of a specific color of light delivered to brain tissue via an implant.
The light is flickered as fast as 1,000 times a second, the frequency at which neurons operate. Optogenetics has only recently become usable in primates, the researchers said.
For the project, the researchers will produce completely reversible “injuries” in the brains of lab animals by temporarily turning off specific parts of the brain. They will then study how the brain might rewire itself to deal with that tissue becoming unavailable.
“There are many advantages to using optogenetics instead of drugs or lesions,” said Karl Deisseroth, associate professor of bioengineering and of psychiatry and behavioral sciences at Stanford, who pioneered optogenetics. “You are in no way injuring the animals, because as soon as you turn the light off they are back to normal, and it is also a lot cheaper, easier and more precise to use.”
With the insights gained from these studies, team members hope to develop prosthetic computer chips that mimic and replace the computational role of injured regions of the brain. “Ultimately, this is aimed at trying to help people who’ve suffered a brain injury, in an entirely new way,” Shenoy said.