Does Breathing Shape Our Brain? New Outstanding Evidence
Breathing brain.
The fudamentals
Breathing is something we do automatically, without thinking. We often forget about it, but let me remind you of something. Our average respiration rate at rest, as adults, is from 12 to 16 breaths per minute.
As we all know, this homeostatic process allows the oxygen in the air we inhale to enter the blood. At the same time, CO2 leaves the bloodstream and reaches our lungs which are ready to discard it via exhaling. And yet there’s much more than that.
Does breathing shape our brain?
In the last few years, researchers have been studying how breathing is related to our emotions, one uncharted territory of scientific psychology. They eventually started to investigate how breathing shapes the brain.
Brainwaves as a tool to examine the influence of breathing in brain.
The key to understanding this link is to look closely at the gamma oscillations. These are a special type of so-called ‟brainwaves”; rhythmic fluctuations that are generated by neural tissue in response to neural activity. The various kinds of oscillations differ in frequency. Gamma oscillations span the range of 25-100 Hz.
When we are learning something new, our brains produce gamma oscillations.
It has already been noticed2 that respiration affects the modulation of odor-evoked gamma oscillations. The same is true4 for emotion-induced oscillations, especially fear and anxiety.
It seems that the center for such outputs lies in the amygdala. Stimulating the amygdala increases the respiratory rate as a result of delta oscillations production in the olfactory bulb. If one electrically stimulates a particular spinal nerve region (the C4 ventral root), which is connected to the limbic system where the amygdala lives, it is possible to burst our breath.
Yes, it does!
A natural question that arises is whether the olfactory system is somehow special in this regard, or if these astonishing results remain true when considering other brain areas. It turns out that4 the olfactory system does have a certain importance, mainly due to evolution.
The cerebral cortex has always maintained a link with the olfactory system, and only later did it adapt so as to expand its influence on other sensory systems. Our nose has acted as a fast way to perceive eventual damages coming from the environment surrounding us since prehistoric times.
Nonetheless3, breathing also shapes other areas of the brain. Measuring at the same time the breathing rhythm and the neural activity in awake mice, researchers have found that both delta oscillations and gamma oscillations influence the barrel cortex.
A crucial role in this is still played by the olfactory bulb, which when is removed3 causes a notable decrease in the respiration frequency. In particular, the delta oscillations are reduced by 80-90%.
New outstanding evidence
A group of scientists followed the road that these seminal achievements paved. They considered an additional factor – the neural gain – to develop a model that describes the influence of breathing rhythms on our cognition, emotions, and perception. Loosely speaking, the neural gain is an amplifier of neuronal activity; augmenting the gain leads to an increase of the electrical activity along the nerve cell (an action commonly defined as ‟neurons firing”), and vice versa, decreasing the gain inhibits neurons.1
According to their most recent paper on this topic1, delta oscillations modulate sensory inputs and responses. Depending on the neuron firing rates, there are alterations in blood temperature and oxygenation, as well as arterial pulsation. The significant aspect here is that, even for small changes in visceral rhythms, the perception of external stimuli sensations (such as smell, sight, etc.) is highly influenced.
Moreover, since gamma oscillations can alter synaptic plasticity, the way we breathe might have a tremendous effect on our brain. Intranasal or intraoral breath, deep or shallow, and so forth – might have a long-term effect on our health.
For example, intranasal breathing specifically modulates hippocampal theta rhythms as well as performance on memory and emotion tasks.modulates hippocampal theta rhythms and5 Based on these findings, Allen, M. et al. suggest that intranasal respiration plays a dominant role in modulating slower neural oscillations associated with top-down computations, and in particular those that regulate affective and motivational processing.1
The post-COVID-19 hypothesis
Although more research is needed before drawing precise conclusions, there are already some relevant elements supporting this hypothesis. For instance, there’s the COVID-19 pandemic. Indeed1, of the more than 600 million people who recovered from COVID-19 as of November 2022, it is estimated that about 15% have suffered (or are still suffering) from long-covid effects despite the absence of any physiological damage.
The reasons are not completely clear, but scientists suspect that many of these consequences may be related to how the patients’ ways of breathing have been changed by this infectious disease.
Takeaway
The good news is that one can learn to regulate and control the rhythm of the breath, as soldiers and snipers do during their training. This could lay1 the foundation for new insights that could help doctors treat some kinds of illnesses, psychiatric disorders, and mental health symptoms such as depression, panic attacks, and anxiety.
In a sense, this is not so different from what physical activity does to our brain: when we exercise, our body releases endorphins, chemical signals that ‟cheat” our brain and make us feel happier, also reducing our pain.
We can therefore conclude that this discovery is opening the doors to plenty of yet-to-be-answered questions. Questions that will surely shed some light on the relationship between our breathing and seemingly unrelated matters. It will take some time to elaborate on the new hypothesis and apply the results in the medical field. However, in the end, the world will feel the difference by using more strategies to cure a range of illnesses.
That’s all. Thanks for reading, stay informed.. and breathe!
References
[4] Homma, I.; Masaoka, Y. (2008). Breathing rhythms and emotions. Exp. Physiol., 93(9), 1011-21
