Finally, modern medical science has uncovered the mechanism that induces a sense of calm in a person who takes deep, slow breaths – a key concept of Yoga, which originated in ancient India. A team from Stanford University School of Medicine identified a small group of neurons that communicate in the brain’s respiratory control centre with the structure responsible for the overall feeling of well-being.
As reported by www.upi.com it has long been known that controlled breathing can induce a sense of calm in a person. Healthcare providers often prescribe breathing-control exercises for individuals with stress disorders, and the practice of controlling breathing in order to shift a person’s consciousness from a frantic state to a more meditative one is a core element in Yoga and meditation.
Dr Mark Krasnow, professor of biochemistry at Stanford, and colleague Dr Kevin Yackle, former graduate student at Stanford and faculty fellow at the University of California, San Francisco, are behind the latest discovery. In a mouse study in 1991, researchers discovered a tiny cluster of neurons linking respiration to relaxation, attention, excitement and anxiety located deep in the brainstem in an area called they refer to as the pacemaker for breathing. The same structure was later found in humans.
In a press release Dr Krasnow explained that “the respiratory pacemaker has, in some respects, a tougher job than its counterpart in the heart. 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. The researchers wondered if different subtypes of neurons within the respiratory control centre might be in charge of generating these different types of breath.
Dr Krasnow and Dr Yackle searched through public databases to create a list of genes that are preferentially activated in the part of the mouse brainstem where the breathing-control centre is located, known as the pre-Botzinger complex or preBotC. They identified more than 60 separate neuronal subtypes that were physically differentiated from one another by their gene-activation signatures. They were able to use these genes and their protein products as markers to pinpoint the different neuronal subtypes and systematically assess the role of each neuronal subpopulation in lab mice. Researchers could then selectively destroy any one of the neuronal subtypes and observe how the loss of a particular subtype affected the animal’s breathing.
They then studied the respiratory role of another subpopulation of 175 preBotC neurons distinguished by their shared expression of two genetic markers known as Cdh9 and Dbx1. Their analysis of similar experiments suggested that the neurons did not regulate breathing, but rather spied on it and reported their findings to another structure in the brainstem known as the locus coeruleus, which sends projections to every part of the brain and drives arousal by waking from sleep, maintaining alertness and can trigger anxiety and distress. So, given the scientific evidence, sessions of deep, slow breathing should be adopted by everyone as part of their daily fitness regime.
