“What we think was going on” was that the disabled neurons normally would detect activity in other neurons within the pacemaker
that regulate rapid breathing and sniffing, says Dr. Kevin Yackle, now a faculty fellow at the University of California, San Francisco, who, as a graduate researcher at Stanford, led the study.
Whether deep breathing has its own, separate set of regulatory neurons
and whether those neurons talk to parts of the brain involved in soothing and pacifying the body is still unknown, although the scientists plan to continue studying the activity of each of the subtypes of neurons within the pacemaker.
The research, on a tiny group of neurons deep within the brains of mice, also underscores just how intricate
and pervasive the links are within our body between breathing, thinking, behaving and feeling.
To better understand why, the researchers next looked at brain tissue from the mice to determine whether
and how the disabled neurons might connect to other parts of the brain.
The scientists confirmed that idea in a remarkable study published last year in Nature,
in which they bred mice with a single type of pacemaker cell that could be disabled.
But when the mice were placed in unfamiliar cages, which normally would incite jittery exploring
and lots of nervous sniffing — a form of rapid breathing — the animals instead sat serenely grooming themselves.
