What yogis know


The practice of pranayama — controlling one’s breath to shift from an aroused state to a more meditative one — has long been a core component of yoga. Now, Stanford researchers have pinpointed the brain cells behind tranquility-inducing breathing.

In a March 31 Science paper, they identified a handful of nerve cells in the brainstem that connect breathing to relaxation, attention, excitement and anxiety. The neuron cluster was first discovered in mice; an equivalent structure exists in people.

“There are many distinct types of breaths: regular, excited, sighing, yawning, gasping, sleeping, laughing, sobbing,” says senior author Mark Krasnow, MD, PhD, professor of biochemistry. “We wondered if different subtypes of neurons within the respiratory control center might be in charge of generating these different types of breath.”

The researchers combed through public databases to find genes that are preferentially activated in the mouse brainstem cluster, called the pre-Bötzinger complex. They identified more than 60 subtypes, which they could selectively destroy based on each one’s unique signature of active genes.

When they eliminated one type of neuron in mice, they found them to be more mellow than their un-bioengineered brethren. They also found that there were fewer fast “active” and faster “sniffing” breaths, and more slow breaths associated with chilling out.

The researchers hope that understanding this neuron cluster’s function will lead to therapies for stress, depression and other negative emotions.