Scientists say they have discovered why people wake up for brief periods while sleeping, which may have more serious implications for sudden infant death syndrome (SIDS) and sleep apnea.
Published in Science Advances, the research looked at so-called sleep arousals, moments when a person can subconsciously awaken for a few seconds to more than a minute. They found a link between these periods and the activity of neurons in the brain.
“There’s been a big debate in the past as to why, when you sleep, you have quite a few of these sleep arousals,” co-author Ronny Bartsch from Bar-Ilan University in Israel told IFLScience. “We came up with this hypothesis that arousals during sleep are from neuronal noise from brain neurons.”
Neuronal noise is the activity of your neurons when they’re in a rest state. They found that random neuronal noise may excite wake-controlling neurons above a certain level, which causes you to wake up, if only briefly. Each person has several short sleep arousals every night.
“Sleep arousals can last on the order of a second to a minute,” said Bartsch. “Usually they are quite short, and you won’t remember them in the morning. The problem is when they get too long, you start to wake up and do other things.”
The findings were not made in humans but rather in zebrafish. While that might seem a little odd, zebrafish are known to be ectotherms – which means they keep their body temperatures at the same as their environment.
“This is very similar to young infants that have an ectothermic trait,” lead author Hila Dvir, also from Bar-Ilan University, told IFLScience. “Concerning the sleep arousals, the zebrafish has a very similar sleep arousal characteristic as humans.”
The most important thing here is the role temperature plays in this process for infants. On a linear scale, higher temperatures are more likely to reduce the amount of neuronal noise, thus a less interrupted sleep. Colder temperatures and you’re going to wake up more often.
And that’s important, because this research may have implications for SIDS and sleep apnea, which can obstruct breathing and be fatal. If an infant is sleeping in a warmer room, it will be more likely to sleep through certain alarming incidents, such as getting their head stuck in a blanket, leading to oxygen depletion in the brain. A lower temperature, while the baby may sleep less soundly, means they’re also more perceptible.
The study could lead to a new generation of sleeping aids, namely medication, that target neuronal noise and improve sleep quality in adults. Conversely, medication that increases neuronal noise could help reduce the risk of life-threatening events like SIDS.
