Stressful thoughts can set the heart pounding, sometimes with such deep force that we worry people can hear it. Anxiety can trigger the irregular skittering of atrial fibrillation. In more extreme and rarer cases, emotional turmoil from a shock — the death of a loved one, a cancer diagnosis, an intense argument — can trigger a syndrome that mimics a heart attack.Powerful signals travel from the heart to the brain, affecting our perceptions, decisions and mental health.
These internal signals, most of which we are wholly unaware of, may even hold clues to one of the grandest scientific puzzles of all — what drives human consciousness.Coalitions of cells in the brain exert exquisite control over the heart. In some parts of the brain, more than 1 in 3 nerve cells influence the heart’s rhythm, Tallon-Baudry and her colleagues reported in 2019 in the. One of these brain regions, the entorhinal cortex, is famous for its role in memory and navigation.
With each flash of a light, delivered through a fabric vest worn by the mice, muscles in the heart ventricles contracted, slamming blood out of the heart and into the body. “It was incredibly exciting to see these really precise heart contractions being evoked with light just delivered through the skin,” Chen says.
“Being able to manipulate the heart in this way,” Tallon-Baudry says, “opens all sorts of ways to look at things that are much more subtle and might not be related to anxiety at all.” The precise control of optogenetics could help researchers investigate the heart’s influence on perceptions, decisions and memory — some of the key attributes that shape how a thinking, remembering, feeling person experiences the world.
That’s what Strick and colleagues have done with various organs — stomach and kidney, for instance — and the brain. Some of the most tantalizing connections he has found are between the adrenal glands, which pump out fight-or-flight hormones in an emergency, and specific brain regions, especially neural locales that control muscles.
But the experiment yielded a worrisome signal: rhythmic, collective activity in the nerve cells that seemed to be created by the pump. “Every neuroscientist knows pump artifacts and hates them,” Egger says. “It is extremely likely that human brains do this,” Egger says, though that remains to be shown. Also unclear is what the brain might do with this pulse information or how it might be used to take measure of the body’s internal state. “What the brain needs this fast pathway for is completely unknown,” she says. “We just know that it happens.”Brain cells can take the heart’s pulse directly. When heart muscles squeeze , blood is pumped out into vessels, including those in the brain .