How the Brain Induces Deep Sleep to Speed ​​Up Recovery

How the Brain Induces Deep Sleep to Speed ​​Up Recovery

Mariana Lenjaro and nature magazine

Immune cells rush to the brain and promote deep sleep after acute cardiovascular diseasein accordance with new research involving both mice and humans. This heavy sleep aids recovery by making it easier inflammation in the heartthe study showed.

The results, published October 30 in the journal Naturecan help you navigate caring for people after a heart attack” says co-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. “Adequate sleep and rest after a heart attack are important for long-term heart recovery,” he notes.

The implications of the study go beyond acute cardiovascular disease” says Rachel Rowe, a sleep and inflammation specialist at the University of Colorado Boulder. “With any injury, your body’s natural reaction is to help you sleep so your body can heal,” she says.

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The heart needs sleep

Scientists have long known that sleep and cardiovascular health linked. For example, people who sleep poorly are at higher risk of developing high blood pressure than those who sleep soundly. But How does cardiovascular disease affect sleep? has been less studied.

To find out more, the authors induced heart attacks in mice and examined the animals’ brain waves. The researchers found that these mice spent significantly more time in slow wave sleep — a stage of deep sleep associated with healing — than in mice that did not have a heart attack.

Next, the authors tried to understand what causes this effect. One obvious place to look was the brain that controls sleepMcAlpine notes. After a heart attack, immune cells trigger a massive explosion of inflammation in the heart, he said, and researchers wondered whether these immune changes also occurred in the brain.

The team found that after the mouse suffered a heart attack, immune cells called monocytes flooded its brain. These cells produce large amounts a protein called tumor necrosis factor (TNF), which is an important regulator of inflammation. and also promotes sleep.

To confirm that these cells were associated with increased sleep, the researchers prevented the accumulation of monocytes in the brains of rodents. As a result, “the mice no longer had the same increase in slow-wave sleep after a heart attack,” McAlpine says, supporting the theory that an influx of monocytes into the brain helps improve sleep after a heart attack. Similar experiments have confirmed the role of TNF as a messenger for brain cells that induce sleep.

Dormant towards recovery

To understand the purpose of the extra sleep, the researchers repeatedly interrupted slow-wave sleep in mice that had suffered a heart attack. The team found that these mice had more inflammation in both the brain and heart, and had a much worse prognosis than mice that were allowed to sleep peacefully after a heart attack.

The authors also studied people who experienced acute coronary syndromea term for conditions, including heart attack, that are caused by a sudden decrease in blood flow to the heart muscle. Those who reported poor sleep in the weeks following such an episode had a higher risk of developing heart attacks and other serious cardiovascular problems over the next two years than those who slept well.

Given the results, “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 hospital settings, where tests and procedures should ideally be carried out during the daytime to minimize sleep interruptions.

She adds that the findings highlight the bidirectional relationship between sleep and the immune system. “When your grandmother says, ‘If you don’t get enough sleep, you’ll get sick,’ there is some truth to that.”

This article is reproduced with permission and has been first published October 30, 2024.