Engineering a Photo-Switch for Nerve Cells in the Eye and Brain

Chemists and vision scientists at the University of Illinois at Chicago have designed a light-sensitive molecule that can stimulate a neural response in cells of the retina and brain — a possible first step to overcoming degenerative eye diseases like age-related macular degeneration, or to quieting epileptic seizures.

Their results are reported online in the journal Nature Communications.

Macular degeneration, the leading cause of vision loss in people over 50, is caused by loss of light-sensitive cells in the retina — the rods and cones.

"The rods and cones, which absorb light and initiate visual signals, are the broken link in the chain, even though what we call the ‘inner cells’ of the retina, in many cases, are still potentially capable of function," says David Pepperberg, professor of ophthalmology and visual sciences in the UIC College of Medicine, the principal investigator on the study.

"Our approach is to bypass the lost rods and cones, by making the inner cells responsive to light."

Pepperberg and his colleagues are trying to develop light-sensitive molecules that — when injected into the eye — can find their way to inner retinal cells, attach themselves, and initiate the signal that is sent to the brain.