Here’s Why You Fall Asleep When You’re Bored

The process that triggers sleep during periods of boredom also offers a pathway for developing less addictive, more therapeutic sleep aids.

Students maybe should be forgiven for falling asleep during boring classes, according to new research.

In a study published in the journal Nature Communications that could lead to new treatments for insomnia, scientists in Japan and China found that a tiny area at the forefront of the brain called the nucleus accumbens can induce sleep when the brain lacks stimulation.

“The more excited you are, the more dopamine your brain produces,” study co-author Michael Lazarus, a sleep expert at the University of Tsukuba's International Institute for Integrative Sleep Medicine in Japan, told Seeker. Dopamine is a naturally produced chemical that triggers positives emotions. “If this stops, then we think the nucleus accumbens actually puts you to sleep.”

Lazarus and his colleagues tested mice using drugs and light sensors inserted directly into the rodents’ brains in order to observe their wakefulness. They discovered that a substance called adenosine — an important organic compound that helps transfer energy through living organisms — triggered sleep when coming in contact with receptors in the nucleus accumbens.

They also discovered that caffeine blocked adenosine from stimulating those receptors, further suggesting a link between the nucleus accumbens and sleep.

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But a key takeaway was that adenosine and the nucleus accumbens created “slow wave” sleep that resembled natural slumber, not the pseudo-sleep that over-the-counter and prescription sleeping pills often deliver.

“If you look at brain waves you will see that the shape and frequency of the wave during natural sleep is different than what you would get from sleeping pills,” said the study’s lead author, Yo Oishi of Tsukuba University. “We call that abnormal sleep.”

A sleep aid called benzodiazepine — an ingredient in the Klonopin, a drug that treats anxiety and seizure disorders — helps puts folks to sleep, for example. But the brain waves of a sleeping person might have a frequency of 5 Hertz, or cycles per second, while a sleeper’s brain waves after benzodiazepine might hit 20 Hertz, the researchers said.

In addition to being addictive, those pills often have nasty side effects, including psychosis, added Lazarus. “The most commons sleep aids are not really healthy,” he said. “We think the adenosine system is more natural.”

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The scientists are hoping to devote more research to adenosine. “It’s been known for decades but it’s still a mystery,” said Lazarus. “People don’t even know where it is produced in the brain.”

In the meantime, however, the study’s conclusions could help produce new sleeping pills that are less harsh, said Lazarus, noting that insomnia afflicts as much as 15 percent of the world’s population with rates that are as much as four times as high among seniors.

“It’s a real big problem in any society all over the world,” said Lazarus. “If you don’t sleep enough, it causes a lot of problems, especially for public health.”

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