Study sheds new light on photoreceptivity

Scientists have discovered how to make cells sensitive to light in what may lead to a new approach to treating certain forms of blindness.

The research, published yesterday in Nature (January 27), focuses on a gene called melanopsin. A team from The University of Manchester and Imperial College London found that activating melanopsin in cells that do not normally use it makes them sensitive to light.

'The melanopsin made the cells photoreceptive which tells us that this protein is able to absorb light,' said Dr Rob Lucas, who led the team in Manchester.

He said the classical view of how the eye sees was via the rods and cones in the retina. But over the last few years it had become increasingly accepted that we had a third system which had lain undetected during years of scientific investigation.

'For this latest research, we found that the cell becomes photosensitised and is able to produce a biological signal,' said Dr Lucas.

For years scientists have been exploring ways of restoring light detection to people with diseased retinas. The use of melanopsin may represent an entirely new approach to this problem.