Researchers at four institutions, led by Stanford University and Brown University, have begun the REPAIR project (Reorganization and Plasticity to Accelerate Injury Recovery), an effort with more than $14 million of DARPA funding to learn both how the brain and its microcircuitry react to sudden physiological changes and what can be done to encourage recovery from injury.

The project will yield new brain implant technologies that can both sense the brain’s electrical signals and deliver optogenetic light pulses to neural tissue.

“To access and truly understand the operation of brain microcircuits and their function, the team will pursue a new generation of implantable optogenetic microdevices, with the ultimate aim of achieving a clinically useful, two-way communication link with the brain,” said Arto Nurmikko, a professor of electrical engineering and physics at Brown.

Optogenetic techniques 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 researchers will use optogenetics to produce completely reversible “injuries” in the brains of research 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, said Karl Deisseroth, associate professor of bioengineering and of psychiatry and behavioral sciences at Stanford, who pioneered optogenetics.

As the team’s researchers learn more about brain function in normal operation and during a simulated injury, they hope to gain a better understanding of how to encourage the brain to rewire itself further, said Krishna Shenoy, an associate professor of electrical engineering and of bioengineering at Stanford and principal investigator of the REPAIR project. In instances when the brain’s ability to heal itself reaches a limit, the researchers may find other ways to restore function.

For instance, Shenoy said, the team hopes to develop a new model of the flow of information around the brain and how each part generates the signals needed by other parts. That kind of insight could help lead to the development of prosthetic computer chips that mimic and replace the computational role of injured regions of the brain. These chips might be miniaturized versions of the implants developed in the REPAIR project, which are capable not only of reading neural-electrical signals but also of generating optical-neural signals for use by brain cells.

“Ultimately, this is aimed at trying to help people who’ve suffered a brain injury, in an entirely new way,” said Shenoy.

More info: Stanford University news