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A new kind of brain cell that links breathing rate to alertness has been found in mice. Destroying these neurons made mice very calm and may explain why deep breathing – such as in yoga or meditation – makes us feel relaxed.

Kevin Yackle at the University of California, San Francisco, and his team have dubbed these brain cells “pranayama neurons” in reference to a yoga breathing exercise. They identified them using an existing database of gene activity in different mouse brain cells. The pranayama neurons stood out because they are the only type of brain cell in the hindbrain that makes two particular proteins.

There are only 350 of these neurons in a mouse’s brain, located at its base in a region responsible for controlling breathing. The researchers found that the cells connect to a nearby brain area known to control alertness.


They then genetically engineered three mice so a drug could be used to kill their pranayama neurons, but leave other brain cells untouched. Once these neurons had been destroyed, the animals took more slow breaths. They also spent less time exploring and sniffing, and more time grooming themselves, becoming “super-chilled out”, says Yackle.

Stress reduction

The normal role of these neurons might be to ensure that when mice are more physically active – such as when exploring a new place – their sniffing and fast breathing trigger a rise in alertness, says Yackle. If the same mechanism is at work in people, slower breathing might make these neurons less active and so lower stress levels.

Many kinds of relaxation therapies, such as yoga and meditation, involve deliberately slowing our breathing. Doctors also recommend deep breathing to help combat anxiety or panic attacks.

Miguel Farias of Coventry University, UK, hopes the findings will encourage research into relaxation techniques. “Deep breathing is a very effective way of calming you down,” he says. “It’s a very strong and quick effect.”

But it would be too dangerous to use the approach from this mouse study to help people relax: accidentally destroying other neurons essential for breathing control could be fatal.

However, because the pranayama neurons make different proteins to the other cells in the brain region controlling our breathing, we might be able to design drugs that turn down their activity alone, suggests Yackle.

Journal reference: Science, DOI: 10.1126/science.aai7984