November 1, 2024
3 read me
How does the brain call deep sleep to speed healing
A heart attack releases immune cells that stimulate neurons in the brain, causing restorative sleep.
A good night’s sleep after a heart attack reduces the inflammation of the organ, helping to recover.
Immune cells travel to the brain and promote deep sleep after a of the heartaccording to a new study involving both mice and humans. This heavy slumber helps you recover by relaxing you inflammation of the heartresearch found.
The findings were published on October 30 naturecan help guide Caring for people after a heart attacksays author Cameron McAlpine of the Icahn School of Medicine at Mount Sinai in New York, who studies immune function in the cardiovascular and nervous systems. “Getting enough sleep and rest after a heart attack is important for the heart’s long-term healing,” he says.
The findings of the study go further of the heartsays Rachel Rowe, a sleep and inflammation specialist at the University of Colorado Boulder. “For any type of injury, your body’s natural response would be to help you sleep so your body can heal,” he says.
About supporting science journalism
If you like this article, please consider supporting our award-winning journalism subscribe. By purchasing a subscription, you’re helping to ensure a future of impactful stories about the discoveries and ideas that shape our world.
The heart must sleep
Scientists have known this for a long time sleep and cardiovascular health are linked. People who sleep poorly have a higher risk of high blood pressure, for example, than people who sleep soundly. But how cardiovascular disease affects sleep less studied.
To find out more, the authors induced heart attacks in mice and studied the animals’ brain waves. The researchers found that these mice spent much more time there slow wave sleep – a stage of deep sleep that has been linked to recovery – than mice that didn’t have a heart attack.
The authors then sought to understand what caused this effect. It was an obvious place to look the brain, which controls sleepwarns McAlpine. After a heart attack, immune cells cause a massive burst of inflammation in the heart, and the researchers wondered if these immune changes also occurred in the brain.
The team found that after a heart attack in a mouse, immune cells called monocytes flooded the brain. These cells produced large amounts a protein called tumor necrosis factor (TNF), which is an important regulator of inflammation and it also promotes sleep.
To confirm that these cells were associated with increased sleep, the researchers prevented monocytes from accumulating in the rodents’ brains. As a result, “the mice no longer had this increase in slow-wave sleep after the heart attack,” McAlpine says, supporting the theory that the influx of monocytes into the brain contributes to the promotion of sleep after a heart attack. Similar experiments confirmed TNF’s role as a sleep-inducing brain cell messenger.
Dormant on the road to recovery
To understand the purpose of the extra sleep, the researchers repeatedly interrupted slow-wave sleep in mice that had suffered heart attacks. The team found that these mice had more inflammation in both the brain and the heart, and had a much worse prognosis than mice that were allowed to sleep undisturbed after a heart attack.
The authors also looked at the humans who lived there acute coronary syndrometerm for conditions caused by a sudden reduction in blood flow to the heart muscle, including heart attack. Those who reported poor sleep in the weeks following an event had a higher risk of heart attacks and other serious cardiovascular problems in the following two years than those who slept well.
Given the findings, “clinicians should educate patients about the importance of a good night’s sleep” after a heart attack, Rowe says. This should also be taken into account in the hospital, where tests and procedures should be performed during the day to minimize sleep disruptions.
He added that the findings highlight a bidirectional relationship between sleep and the immune system. “When your grandma says ‘if you don’t get enough sleep, you’ll get sick’, there’s a lot of truth in that.”
This article is and was reproduced with permission first published On October 30, 2024.
