The discovery of a new "cog" in the human body clock that governs sleep will enable significant advances in the treatment of jet lag and sleeping disorders, scientists claim today.

The body clock, which links the cycles of metabolism and behaviour to the cycle of day and night, can be disrupted by old age, disease, international travel and shift work.

The disruption can lead not just to problems with sleeping and eating, but also to serious illness.

However, researchers have discovered a molecule, called c-AMP, that plays an important role in keeping the body clock ticking.

The molecule was discovered in the hypothalamus, a part of the brain that contains cells that synchronise the body clock with the other major organs including the heart, lungs and liver.

The scientists discovered that daily activation of this molecule, or "cog", helps to sustain the body clock's rhythm, by working with the body's genes and proteins. They believe that this could pave the way for new treatments for jet leg and other sleep disorders, in which the body clock is effectively "reset".

The study, published in the journal Science, was led by Dr Michael Hastings, at the Medical Research Council Laboratory of Molecular Biology in Cambridge.

Dr Hastings said that disruption of the body clock through "shift work, old age and neurological disease" was a "significant and growing cause of chronic illness".

He said: "If we can identify ways to control the clockwork we may be able to learn how to reset it when it goes wrong.

"We have found that daily activation of c-AMP signals help to sustain progression of the body clock's rhythm. This is a new way of thinking about how the body clock ticks, the involvement of c-AMP shows that the control mechanism extends into areas of the cell we weren't aware of it working in before.

"This gives us a new way to control the body clock in all of our organs and tissues.''

MRC Technology, the technology arm of the Medical Research Council, has filed a patent application to protect pharmacological methods of manipulating the molecule.

The company hopes that drugs developed using these methods could lead to treatments for genetic sleep disorders. Dr Nicole Mathon, the business manager at MRC Technology, said: "We are hoping that industry will pick up on this interesting discovery so that we can foster a collaboration to start a drug discovery programme."