Here's what switches our sleep button on and off

Ever wondered how you went off to sleep and how you woke after sleep? Researchers claim that they have found two elements which control the act.

Ravi Allada of the Northwestern University and his research team found that high sodium channel activity in these neurons during the day turn the cells on and ultimately awakening an animal, and high potassium channel activity at night turn them off, allowing them to sleep.

Investigating further, the researchers were surprised to discover the same sleep-wake switch in both flies and mice.

Allada said that this oscillation mechanism appeared to be conserved across several hundred million years of evolution, adding that if it's in the mouse, it was likely in humans, too.

The researchers called this a 'bicycle' mechanism: two pedals that go up and down across a 24-hour day and conveyed important time information to the neurons.

That the researchers found the two pedals, a sodium current and potassium currents, active in both the simple fruit fly and the more complex mouse was unexpected.

They discovered that when sodium current was high, the neurons fire more, awakening the animal, and when potassium current was high, the neurons quiet down, causing the animal to slumber. The balance between sodium and potassium currents controls the animal's circadian rhythms.

Allada and their colleagues then wondered if such a process was present in an animal closer to humans. They studied a small region of the mouse brain that controls the animal's circadian rhythms, the suprachiasmatic nucleus, made up of 20,000 neurons and found the same mechanism there.

The study is published in the journal Cell.