Male fruit flies from a long line of monogamous sires show less intelligence than those whose progenitors competed with rivals for multiple females' favours.

London - Scientists believe they have found the switch in the brain that tells our bodies when it is time to sleep.

The discovery, by neurologists at Oxford University, could pave the way for a treatment to combat sleep disorders such as insomnia.

The switch is thought to work by regulating neurons – nerve cells – in the brain. It operates when the body has been awake for too long.

The study, published in the journal Neuron, took fruit flies and removed their sleep homeostat to create insomniac insects.

Researchers say the same system works in the human brain. They are now trying to find out how to activate the sleep switch so that it can be used to treat insomnia.

One of the team, Dr Diogo Pimentel, said: “If we knew what happens in the brain during waking that requires sleep to reset, we might get closer to solving the mystery of why all animals need to sleep.”

Team leader Professor Gero Miesenboeck said there are probably two mechanisms that regulate sleep patterns. One is the body clock, the circadian rhythm which attunes humans and animals to the 24-hour cycle of day and night.

The other is the sleep homeostat, which keeps track of waking hours and makes the body nod off.

“When you’re tired, these neurons in the brain shout loud and they send you to sleep,” he said.

Flies without the switch did not have regular sleep patterns and were prone to nodding off. They had severe learning and memory deficits, in the same way that sleep loss causes problems in humans. - Daily Mail