Fiber-optic technology revolutionized the telecommunications industry and may do the same for brain research and medical treatments.

Researchers from Washington University in St. Louis have created a new kind of fiber-optic device to manipulate neural activity deep in the brain. The device, called PRIME (Panoramically Reconfigurable IlluMinativE) fiber, delivers multi-site, reconfigurable optical stimulation through a single, hair-thin implant.

“We have thousands of independent channels inside a single fiber to allow you to emit in the deep brain,” said Song Hu, a professor of biomedical engineering.

In order to understand complex brain circuits, researchers need to deliver light to hundreds or thousands of different points in the brain.

“We can actually inscribe tiny mirrors inside the fiber, and then it can reflect the light. The light can be bounced and emit from the side,” said Hu. “You can do that to hundreds or thousands of different locations across multiple brain regions.”

Hu compared the single fiber to a controllable disco ball in the brain. His team included research assistant professor Shuo Yang. Yang used ultrafast-laser 3D microfabrication to inscribe thousands of grating light emitters (acting as mirrors) into a fiber the width of a human hair.

Hu collaborated with the laboratory of Adam Kepecs, a professor of neuroscience and of psychiatry at WashU Medicine, enabling new neuroscience studies at WashU Medicine.

“We are working with the team of Dr. David Holtzman,” said Kepecs. “They have engineered models of Alzheimer’s in mice for (PRIME) research ”

Hu’s goal for PRIME is to one day treat patients suffering from different diseases in real-time.

“We need to record the brain signal to see what’s wrong, and then at the right moment we want to delivery therapy, therapeutic intervention, into the brain region to reverse a wrong, to make it right,” said Hu. “In order to do this you need a bidirectional device.”