Meet the Stepford flies. US scientists have created genetically modified flies they can remotely control with laser light.

At the flick of a switch the researchers use the laser to make the flies jump, beat their wings and fly on command - echoing the way the Stepford husbands use a handheld device to control their wives in the 2004 remake of the classic film.

The scientists hope the freakish experiments will show them how nerve activity relates to behaviour, perhaps one day helping to restore feelings and movement to people who have lost nerve cells through injury or disease.

Gero Miesenbock, who led the research at Yale University school of medicine in Connecticut, said: "One could use this method to restore neural signals that have been lost. It represents a significant step in moving neuroscience from passive observation to the active and predictive manipulation of behaviour."

People suffering from spinal cord injuries could even have nerve activity restored, though Professor Miesenbock warned the possibility is still "far fetched" at the moment.

Prof Miesenbock and graduate student Susana Lima created GM fruit flies that produce a chemical gateway called an ion channel in nerve cells known to control movement and flight. They injected these flies with chemicals that could be activated by ultraviolet light.

Tiny bursts of laser light forced the chemicals through the ion channels, activating the nerve cells. Trapped inside a jar, 60-80% of the flies responded to the light by shaking their legs and flapping their wings.

Prof Miesenbock said the results could show how nerve cell activity and connections are involved in simple movements as well as complex behaviour. The triggered behaviour could last seconds or continue ... depending on whether the neural circuit activated had a feedback loop.

"In the case of the flight circuits it's like pushing a swing. One kick and it keeps swinging back and forth for a while."