Sleep Switch: Scientists Identify Nerve Cells that Promote Slumber

For many, sleep doesn't come so easy. Hitting our head to the pillow may not be quite enough to send us into dream land at the end of the day. Yet researchers at Oxford University's Centre for Neural Circuits and Behavior have recently discovered a sleep switch based on a fruit fly study.

According to background information from the study, this switch works by simply regulating the activity of a handful of sleep-promoting nerve cells or neurons found in the brain. These neurons typically fire as we sleep and dampen down when we're fully rested.

"When you're tired, these neurons in the brain shout loud and they send you to sleep," said Professor Gero Miesenböck of Oxford University, in whose laboratory the new research was performed, via a press release.

Although this research was carried out in fruit flies, many believe that the sleep patterns of these creatures are similar to humans.

"There is a similar group of neurons in a region of the human brain," said Dr. Jeffrey Donlea, one of the lead study authors. "These neurons are also electrically active during sleep and, like the flies' cells, are the targets of general anaesthetics that put us to sleep. It's therefore likely that a molecular mechanism similar to the one we have discovered in flies also operates in humans."

Researchers determined that the body typically uses two main mechanisms to regulate sleep. First, the body clock that works in both animals and humans to put them on a 24 hour cycle day and night schedule. The other sleep mechanism, the 'homeostat,' is a device in the brain that actively keeps track of the body's waking hours and puts it to sleep when rest is needed in order to reenergize.

The fruit fly study helped researchers determine the critical part of the sleep switch. "We discovered mutant flies that couldn't catch up on their lost sleep after they had been kept awake all night," Donlea said, via the release.

Through the study, researchers found that fruit flies stopped moving when they went to sleep, and required more disturbance to wake them up. Yet sleep-deprived fruit flies were more prone to nodding off and showed greater signs of cognitive impairment, which later led to learning problems and memory deficits, as commonly exhibited in humans.

Researchers are hopeful that this new discovery could potentially aid in new treatments to help those with sleep disorders.

Sleep disorders can range from snoring to sleep apnea, insomnia, sleep deprivation or even restless leg syndrome--all of which should be checked out by your primary care doctor if you are exhibiting symptoms of these or other health issues.

"The big question now is to figure out what internal signal the sleep switch responds to," said Dr. Diogo Pimentel of Oxford University, the other lead author of the study. "What do these sleep-promoting cells monitor while we are awake?"

'"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."

What do you think?

More information regarding the study can be found via the journal Neuron.