New Technologies Could Provide Insights on the Brain Injury and Recovery Processes

New techniques in Optogenetics will 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.

Researchers at Stanford University (CA, USA), Brown University (Providence, RI, USA), the University of California San Francisco (USA) and University College London (UCL; United Kingdom) have joined the forces of 10 professors and their research teams in the Reorganization and Plasticity to Accelerate Injury Recovery (REPAIR) project, which will use optogenetics to produce completely reversible "injuries" in the brains of research animals by temporarily turning off specific parts of the brain via implants that generate light. Together, the team's expertise ranges from neuroscience, neurology, and psychiatry, to semiconductors, optoelectronics, statistical signal processing, machine learning, and brain modeling.

The research team hopes to develop a new model of the flow of information around the brain, and elucidate how each part generates the signals needed by other parts. It is hoped that the insights from the research would lead to the development of prosthetic computer chips that mimic and replace the computational role of injured regions of the brain. These same 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.

"There are many advantages to using optogenetics instead of drugs or lesions,” said Karl Deisseroth, Ph.D., an 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.”

"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,” added Arto Nurmikko, Ph.D., a professor of electrical engineering and physics at Brown.

Optogenetics is an emerging field combining optical and genetic techniques to probe neural circuits within intact mammals and other animals, at the high speeds needed to understand brain information processing. This millisecond-scale temporal precision is central to the concept of optogenetics, which allows probing the causal role of specific action potential patterns in defined cells. By analogy, traditional genetics is used to probe the causal role of specific proteins within cells, via "loss-of-function” or "gain of function” changes in these proteins, to probe how the genetic code controls development and behavior. Correspondingly, to probe the neural code, optogenetics must allow addition or deletion of precise activity patterns within specific cells in the brains of intact animals, including mammals.

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Stanford University
Brown University
University of California San Francisco
University College London