What Effect Does Breathing Have on the Brain?

In the course of your life, if you're fortunate enough to survive to 80, you could take up to a billion breaths, breathing and exhaling enough air to fill at least 50 Goodyear blimps. We inhale oxygen to feed our cells and tissues with roughly 20,000 breaths every day, exhaling carbon dioxide that accumulates as a result of cellular metabolism. People typically pass away within minutes if their breathing ceases since breathing is so vital to life.

We often take this behaviour for granted since it is so automatic. However, breathing is a physiological wonder that is both very dependable and adaptable. Prior to an increase in physical activity as well as in response to stress or arousal, our breathing rate can change nearly instantly. And you might not have even realised how your breathing alters to suit other behaviours like eating, talking, laughing, and sighing since they are so perfectly synchronised with breathing. The controlled breathing techniques used in yoga and other traditional contemplative practises are proof that breathing can affect your state of mind.

Researchers have recently started to understand some of the fundamental brain mechanics of breathing and its numerous effects on the body and mind. Neuroscientists discovered a network of neurons in the brainstem that controls the rhythm of breathing in the late 1980s. This revelation served as a catalyst for further research into how the brain coordinates breathing with other behaviours. At the same time, there is growing evidence that breathing may have an impact on the activity of numerous brain regions, including those with significant involvement in emotion and cognition.

Jack L. Feldman, a neuroscientist at the University of California, Los Angeles, and coauthor of a recent article on the interaction between breathing and emotion in the Annual Review of Neuroscience, asserts that "breathing has a lot of jobs." We continually change our posture and metabolism, and it has to be linked with all these other actions, so it's quite hard.

Each breath is a symphony of the brain, muscles, and lungs

When you breathe in, oxygen-rich air fills your lungs, which then transport that oxygen throughout your body via your bloodstream. About 500 million small sacs called alveoli, which are found in a typical human pair of lungs, allow gases to move between the airway and bloodstream. This interface has a total surface area of around 750 square feet, which is slightly more than the size of a standard San Francisco one-bedroom apartment and slightly less than a racquetball court.

Humans, as well as other mammals, cram a significant amount of surface area onto our chests, according to Feldman. More gas is exchanged per second with greater surface area.

But it can't be done only by the lungs. They resemble floppy tissue bags. Feldman asserts that for this to function, the lungs must be used as bellows. The diaphragm muscle at the base of the chest cavity contracts with each breath, decending by about half an inch. The rib cage is also moved up and out by the intercostal muscles between the ribs, which helps to expand the lungs and draw in air.

(If you've ever eaten barbecued ribs, you've probably encountered intercostal muscles; if you've ever had the wind knocked out of you by a blow to the stomach, you know all about the diaphragm.)

Only during inhalation do these muscles contract while at rest. Passively, the lungs expand and the muscles relax to cause exhalation. Diverse muscle groups contract while you exercise in order to drive air out of your lungs and quicken your breathing.

The breathing muscles receive their commands from the brain, as opposed to the heart muscle, which includes pacemaker cells that regulate its rhythm. Given the significance of those brain impulses in sustaining life, it took an unexpectedly long time to find them. Galen, a Greek physician who saw that gladiators whose necks were broken over a certain level were unable to breathe regularly, was one of the first to wonder about their origin. Later research focused on the brainstem, and in the 1930s British physiologist Edgar Adrian showed that a goldfish's dissected brainstem still produces rhythmic electrical activity. Adrian believed that this activity was the pattern-generating signal that underlies respiration.

However, it wasn't until the late 1980s that Feldman and colleagues were able to pinpoint the precise site of the brainstem respiratory-pattern generator to a network of around 3,000 neurons in the mouse brainstem (in humans it contains about 10,000 neurons). The preBötzinger Complex (preBötC) is the current name for it. Neurons there display cyclic electrical activity bursts that are transmitted by intermediary neurons to control the breathing muscles.

Feldman claims that over time, some individuals have believed Bötzinger must have been a well-known anatomist, possibly a German or Austrian. However, the name actually came to him in a flash over a meal at a scientific meeting where he felt a colleague was ready to make an improper claim to the discovery. Feldman raised his glass in salute and proposed renaming the brain region after the wine, which was from the Bötzingen region of Germany. y. The others concurred that perhaps the wine had lubricated them, and the name stuc K. Feldman asserts that "scientists are just as strange as everybody else." "We enjoy doing things like this," 

Identifying The Rhythm-makers Of Breath

Feldman's subsequent research has largely centred on figuring out how precisely neurons in the preBötC produce the breathing rhythm.

This research has also paved the way for his lab and others to examine how the brain coordinates breathing with other behaviours that call for respiratory changes.

One intriguing example is sighing. Long, deep breaths can convey a variety of emotions, including melancholy, elation, resignation, desire, and tiredness. However, it is believed that all mammals sigh, not just humans. This may be because, in addition to its expressive qualities, sighing serves an important biological purpose. Every few minutes, humans sigh, and each one starts with an air intake that is roughly twice that of a regular breath. Similar to how blowing into a rubber glove opens the fingers, scientists believe this aids in popping open collapsing alveoli, the tiny chambers in the lung where gas exchange takes place. There are several pieces of evidence for this claim: 

for instance, have been demonstrated to enhance lung function and keep patients' blood oxygen levels stable.

Feldman and colleagues found four small groups of neurons that they believe are in charge of producing sighs in mice in a study that was published in Nature in 2016. Two of these groups of neurons are located close to the preBötC in the brainstem, and they communicate with the other two groups, which are located inside the preBöt, via signals. C. The rats stopped sighing but their breathing remained irregular when the researchers used a highly selective toxin to kill these preBötC neurons. However, rats moaned 10 times more frequently when scientists gave them injections of neuropeptides that activate the neurons.

According to the researchers, preBötC receives instructions from these four groups of neurons to disrupt its routine of taking normal-sized breaths and order up a deeper breath.

Additionally, the preBötC functions to coordinate breathing with other actions. Neuroscientist Kevin Yackle and colleagues recently used mice to examine interactions between breathing and vocalisations. Yackle and colleagues worked with Feldman on the sighing paper. Newborn mice make ultrasonic sounds that are too high-pitched for people to hear when they are taken from their nest. Like the syllables in human speech, there are usually many cries at regular intervals within a single breath, according to Yackle, who is currently at the University of California, San Francisco. You have a slower breathing rhythm, which is nested within a faster vocalisation rhythm, the speaker claims.

The researchers began with the larynx, the area of the throat responsible for sound production, to understand how this works. They located the larynx-controlling neurons using anatomical markers and traced their connections to a group of cells in the brainstem they called the intermediate reticular oscillator (iRO). The researchers discovered using a variety of methods that killing or inhibiting iRO neurons eliminates the capacity to vocalise a cry, while stimulating them increases the amount of cries per breath.

The iRO neurons continued to fire in a predictable fashion when the researchers cut out slices of brain tissue. According to Yackle, "These neurons produce a rhythm that is precisely like the animal's cries, where it is quicker than yet nested within the preBötC breathing rhythm."

Regulating The Brain's Rhythm

According to recent studies, breathing may have an unexpectedly large impact on how well people do on a variety of lab tests. A person's ability to perceive a light touch and tell apart three-dimensional objects might be affected by where they are in the inhalation and exhalation cycle. According to one study, breathing deeply right before a cognitive task tends to boost performance. Many people have discovered that these effects only occur when breathing through the nose; mouth breathing does not.

An developing theory explaining how this might function centres on the brain's well-known rhythmic oscillations of electrical activity. Some neuroscientists have argued for decades that these waves, which are frequently measured with electrodes on the scalp, reflect communication between dispersed brain regions that may underlie significant aspects of cognition. They capture the cumulative activity of thousands of neurons. For instance, they might involve the brain's integration of sensory data processed separately in the auditory and visual lobes to create what we perceive as a seamless sense of a scene's sounds and images. Some experts have even suggested that this kind of synchronised activity might be the source of awareness (needless to say, this has been hard to prove).

A growing body of research indicates that some of these oscillations may be paced by breathing. The breathing cadence affects waves of activity in the hippocampus, a region important for learning and memory, according to study conducted on rodents. The collective electrical activity of neurons in the hippocampus rises and falls at a regular rate while a person is awake; this rate is usually between six and ten times per second. All the investigated animals, including humans, display this so-called theta rhythm.

Peaceful Mind And Controlled Breathing?

Controlled breathing has been used by followers of ancient meditational practises like yoga and others to alter their state of mind for millennia. Researchers' interest in the biological mechanisms underlying these effects and how they can be used to treat anxiety and mood disorders has grown during the past few years.

According to UCLA psychiatrist Helen Lavretsky, one difficulty has been isolating the effects of breathing from other components of these activities. "When you're doing this multi-component intervention where there's stretching and movement, visualisation, and chanting," she says, "it's incredibly hard to discern what's most beneficial." Not to mention the cultural and spiritual elements that numerous individuals associate with the practise.

Lavretsky has worked with neuroscientists and others for many years to study the effects of various styles of meditation on the brain as well as biological stress and immune function markers. She has discovered, among other things, that meditation can help older adults with moderate cognitive impairment, which is a possible precursor to Alzheimer's disease and other types of dementia, perform better on lab tests of memory and change brain connectivity. She has shifted her focus in more recent experiments, which have not yet been published, to determining whether breath control techniques by themselves can be helpful.

Even though I'm a psychiatrist, adds Lavretsky, who is also a licenced yoga instructor, "my research is on how to avoid [prescribing] medicines." She believes that, with more research on which breathing techniques are most effective for certain diseases and how they may be customised to individuals, breathing exercises may be a good alternative for many people. We only need to understand how to use it because we all have this instrument, she argues.