New research published in Nature has shown that after experiencing a heart attack, the heart sends signals to the brain to increase amounts of deep sleep and promote healing.
The study used a mouse model to study the brain and heart after a heart attack. Using high-resolution imaging, cell analysis, and implanted wireless devices, the researchers measured electrical signals from the brain as well as sleep patterns after the mice experienced a heart attack. The researchers compared these results to similar mice who did not experience a heart attack.
The imaging and analysis showed that, after a heart attack, immune cells flooded the brains of the mice and produced large amounts of tumor necrosis factor (TNF), a protein that regulates inflammation and promotes sleep. The mice who had heart attacks also spent much more time in slow wave sleep compared to other mice, which was linked to the immune cell changes. Slow wave sleep has been associated with healing in other studies. To confirm the purpose of the extra sleep, the researchers disrupted the slow wave sleep in some mice and compared their outcomes to mice with uninterrupted sleep. The mice with interrupted sleep had more inflammation in the heart and the brain and had a worse prognosis compared to the uninterrupted mice.
The authors stated that this study confirms that the heart uses the immune system to signal the brain and promote sleep after a cardiovascular injury. Both the drive to sleep and the amount of sleep were increased in mice who had a heart attack, which promoted healing and recovery. Sleep has been previously linked to heart health in many studies, and those who get poor sleep are more likely to have high blood pressure and experience cardiovascular disease. This study further links heart health to amounts and quality of sleep.
Sources: Nature, Science Daily
