By Jill Sakai
Photography by Craig Mahaffey ’98 & Ashley Jones
Stephen Foulger is harnessing new X-ray-sensitive, light-emitting materials, which may enable control of neural activity from outside the skull
Before joining Clemson’s faculty in 1999, Stephen Foulger spent a stint working in the fiber optics industry. Years later, that background drew his interest to a developing field that uses implanted fibers to deliver light signals deep within the brain to trigger neural activity.
Called optogenetics, the experimental technique offers a way to change activity in targeted regions of the brain from outside the skull, using pulses of light delivered to light-sensitive proteins in the neurons. Researchers have tested the approach in animal models to try to restore activity in regions affected by neurodegenerative disease, for example, or to damp down errant neural firing in epilepsy. Foulger, the Gregg-Graniteville Endowed Chair and Professor of Materials Science and Engineering, marveled at the technique’s potential for exploring brain function or treating disease.
“These light-sensitive proteins open or close synapses,” he explains. “You can localize synaptic behavior in regions of the brain using these light-tunneling fibers and these proteins.”
But the need to implant the optical fibers directly into the brain is a major limitation of the technique’s broader use. Researchers must remove a small piece of skull and leave the fibers in place for the duration of an experiment.
With his expertise in designing optical materials, Foulger realized it should be possible to accomplish the task without fibers. He is now working to harness the potential of optogenetics for wider use by designing new light-producing materials that could make the approach noninvasive and bring it within reach for medical applications.
I graduated from Clemson and practiced Ophthalmology for many years in Houston, Texas. I was wondering if you have considered using the light sensitive proteins in the retina rods and cones. A wave length in the visual spectrum would probably be needed besides x-rays. If they could be implanted in the occipital cortex and stimulated to produce light perception, that would be a wonderful thing for a blind person that has no light perception. A receptor placed on the skull and connected to a transmitting wire going to the occipital cortex could possibly transmit wave lengths in the visual spectrum. Possibly some other way to do it. Thanks. Gene Alford, MD. ‘57 in Textile Chemistry