Your mom was right. Slow, even breathing can calm you down. Now scientists know why.
Tests in mice pinpoint the brain cells that are triggered when an animal breathes slowly. These cells link breathing to mood and activity.
In mice and in humans, this cluster of cells is found deep in the brain stem, in what’s known as the breathing center.
“We’re hopeful that understanding this center’s function will lead to therapies for stress, depression and other negative emotions,” said Jack Feldman, a professor of neurobiology at UCLA who worked on the study.
It might even lead to a better way to prevent sudden infant death syndrome, or SIDS.
The team built on decades of work looking for the brain cells that control the effects of breathing. Some work without conscious effort, but others can be controlled.
This particular little group works a little like the brain cells that control the heart, said Dr. Mark Krasnow, a Howard Hughes Medical Institute biochemistry professor at Stanford University who oversaw the study.
“Unlike the heart’s one-dimensional, slow-to-fast continuum, there are many distinct types of breaths: regular, excited, sighing, yawning, gasping, sleeping, laughing, sobbing,” said Krasnow.
“We wondered if different subtypes of neurons within the respiratory control center might be in charge of generating these different types of breath.”
The team worked with mice, genetically engineering them so that these brain cells, called the pre-Bötzinger complex, could be controlled with toxins made by diphtheria bacteria.
They were hoping the mice would immediately breathe more slowly once injected. As it turned out, it took a few days to notice the change in their behavior, the team reported in the journal Science.
“If you put them in a novel environment, which normally stimulates lots of sniffing and exploration, they would just sit around grooming themselves,” said Dr. Kevin Yackle, who did the work while a graduate student at Stanford and who’s now at the University of California San Francisco.
Help for stress disorders
If they can find a way to make the same thing happen in people, it could help treat some anxiety disorders and perhaps even sudden infant death syndrome (SIDS).
This center might be what helps people wake up quickly from a deep sleep if something interrupts their breathing, and it may be it doesn’t do its job correctly in some sleeping infants, the researchers said.
“Indeed, fast or erratic breathing in humans increases alertness and can cause anxiety and even panic,” the team wrote in their report.
“Conversely, slow and controlled breathing has long been known by practitioners of pranayama yoga to induce relaxation, and related approaches have proven useful for anxiety syndromes and other stress disorders.”
So a pill that has the same effect as a nice, deep-breathing session could help treat anxiety, while something to activate that center might help babies predisposed to SIDS, the researchers said.