According to research published online today in Nature, the team from Imperial College London and the University of Manchester, have discovered that activating the melanopsin gene in the nerve cells causes them to become light responsive, or photoreceptive.

Using mouse cells, the researchers found that melanopsin could be used to make neurones light responsive. They found that as well as being sensitive to blue light, melanopsin uses light at different wavelengths to regenerate itself. In some forms of hereditary blindness photoreceptors are lost entirely, but the retinal ganglion cells, the cells which signal to the brain, remain intact. The researchers believe that by activating the melanopsin, these cells may gain the ability to sense and respond to light.

Professor Mark Hankins, from Imperial College London and Charing Cross Hospital, and one of the papers authors, comments: "It is quite remarkable that the activation of a single gene can create a functional photoreceptor. It is an important proof of principle that melanopsin can make non-light sensitive cells receptive to light, and although not a cure, could have applications in treating some forms of blindness."

Dr Rob Lucas, from the University of Manchester, and one of the paper's authors, adds: "The discovery that melanopsin is capable of making cells photosensitive has given us a unique opportunity to study the characteristics of this interesting protein. The textbook view of the eye is that it contains only two light sensing systems, the rods and cones. However, over the last few years it has become increasingly accepted that we have a third system, which uses melanopsin, that has lain undetected during decades of vigorous scientific investigation."

Professor Hankins and Dr Lucas were part of the team who previously discovered a new light detection sys
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Contact: Tony Stephenson
at.stephenson@imperial.ac.uk
44-207-594-6712
Imperial College London
26-Jan-2005