You may not realise it when your alarm clock forces you into a bleary-eyed stupor first thing in the morning, but there's actually a complex chemical process going on inside your brain as you wake up. And scientists now think they've identified the part of the brain that ends periods of light sleep and brings us into a state of wakefulness.

Researchers from Switzerland focussed their attention on a specific neural circuit located between the brain's hypothalamus and thalamus. By stimulating this circuit with pulses of light in a group of mice, the academics could prompt rapid awakenings from sleep and then cause prolonged wakefulness.

Why should we be excited about knowing more about how we get yanked out of our regular sleep patterns? The researchers say it could ultimately help those who are trapped in a long-term coma or vegetative state, and on the flip side, could also help those with sleep disorders, or at least give doctors a better idea of why they aren't sleeping correctly.

"The consequences of sleep perturbations on life quality go far beyond daytime sleepiness and mood alteration," said one of the team, Antoine Adamantidis from the University of Bern. "Cognitive impairment, hormonal imbalance and high susceptibility to cardiac or metabolic disorders are amongst some of the negative impacts frequently associated with subtle chronic sleep problems."

The researchers also found that by inhibiting that same neural circuit - by shutting down the pulses - they could cause the mice to fall into a deeper sleep. While key brain circuits for both the deeper REM (Rapid Eye Movement) sleep and the lighter non-REM sleep had previously been identified, little is known about the underlying mechanisms. The Bern researchers call it a modern neuroscience enigma.

"Even though we made an important step forward, it will take some time before novel therapeutical strategies will be designed based on our results," admits Adamantidis. But there is fresh hope for those suffering from chronic sleep problems - in the US alone, the figure is estimated to be around 50 to 70 million people.

The team found that with enough stimulation, mice could even be brought out from under the effects of an anaesthetic, and while some forms of deep brain electrical stimulation have been tried in the past, this one is far more targeted.

With previous research linking pervasive disorders such as Alzheimer's, Parkinson's, and schizophrenia to sleep problems, this discovery could eventually have a long-lasting impact in various different areas of health.

The research has been published in Nature Neuroscience.