Surprising solution to fly eye mystery

The conventional wisdom would be that one of the products of this enzyme's activity is a chemical 'second messenger' that binds to and activates the channel. However, years of research had previously failed to find compelling evidence for such a straightforward mechanism." - —Professor Roger Hardie, lead author of the study from the University of Cambridge's Department of Physiology, Development and Neuroscience Fly eyes have the fastest visual responses in the animal kingdom, but how they achieve this has long been an enigma. A new study shows that their rapid vision may be a result of their photoreceptors - specialised cells found in the retina - physically contracting in response to light. The mechanical force then generates electrical responses that are sent to the brain much faster than, for example, in our own eyes, where responses are generated using traditional chemical messengers. It had been thought that the ion channels responsible for generating the photoreceptors' electrical response were activated by chemical messengers as is usually the case in cell signalling pathways. However, these results suggest that the light-sensitive ion channels responsible for the photoreceptor's electrical response may be physically activated by the contractions - a surprising solution to the mystery of light perception in the fly's eye and a new concept in cellular signalling. Professor Roger Hardie, lead author of the study from the University of Cambridge's Department of Physiology, Development and Neuroscience, said: "The ion channel in question is the so-called ' t ransient r eceptor p otential ' (TRP) channel, which we originally identified as the light-sensitive channel in the fly in the 1990's.