Circadian rhythm, the internal clock that governs many of the body's functions - including sleep - is typically set by diurnal changes in light and temperature. But new research on the circadian rhythm in fruit flies has shown that their internal clock can be manipulated with vibrations.
The research, carried out by University College London and the city's Queen Mary University, suggests that an animal's own movements can influence its internal clock.
Writing in the journal Science, the researchers report that exposing a fruit fly (Drosophila) to 12-hour cycles of vibration and silence is sufficient to synchronize the fly's internal clock and corresponding daily activity.
"In a nutshell, our research shows that, in flies, the biological clock which regulates most bodily functions can be set - or entrained - not only by light and temperature, but also by mechanical stimuli that excite sensory receptors in the body," said senior study author Joerg Albert of University College London.
"Our research encourages further research into the genetic and cellular basis of how the circadian clock is set," Albert said. "In mammals and humans there has been sporadic, but as yet inconclusive evidence to show if, and how, movement such as scheduled physical exercise can reset the clock."
The study may have implication for humans as well, the researchers report, noting that certain sleep-related conditions may one day be treated with vibration therapy.
"Our experiments offer a novel pathway for setting the circadian clock that may well be relevant for the treatment of clock related diseases, such as insomnia, depression, bipolar disorder," said study author Ralf Stanewsky or University College London.
"It also offers a novel way to set the circadian clock using movement as well as extrinsic entrainment such as ambient light and temperature fluctuations. It could point to the existence of an animal's internal 'own time' that might have to be negotiated with the external 'world time'," he said.