Sources and References
0. Inspired by my reading from Jean-Marie Defossez in a health magazine. Who is Jean-Marie Defossez?
A speaker, author, and facilitator of breathing courses and workshops, Jean-Marie Defossez holds a doctorate in animal biology and specializes in physiology. Trained in numerous therapeutic breathing techniques, notably in the USA, he founded the breathing coach in 2014.
He is notably the author of “Grand Guide du nerf vague” and “Être en bonne santé grâce au nerf vague” (The Great Guide to the Vagus Nerve, and “Being Healthy Thanks to the Vagus Nerve”, published by Jouvence Editions).
NB: His guide / site is a bit too commercial. Not everything is 100% in line with RP, but it's a good start to explore further (if you have time to lose) 😉
Short video of Relaxation and Pranayama – for
Shavasana technique
https://youtu.be/1VYlOKUdylM (1.06’’)
sedinfrance.org: Vagus nerve stimulation (In French)
Chronic stress affects the functioning of the vagus nerve. Excessive or constant stimulation can lead to desensitization. An over-stimulated vagus nerve can become weakened or dysfunctional, leading to a variety of symptoms such as digestive upset, anxiety, chronic fatigue, and difficulty recovering physically and emotionally. When the nerve is constantly stimulated, it can lose its ability to function properly, affecting the balance of the autonomic nervous system and leading to dysfunction.
The vagus nerve also plays an important role in regulating inflammation.
apoticaria.com le-nerf-vague-sentinelle-du-bien-être (in French)
=> When properly activated, the vagus nerve has a positive effect on regulating inflammation. Through acetylcholine, it sends a signal to immune cells (especially those in the intestine) to reduce inflammation as soon as it is no longer necessary.
How is the vagus nerve affecting acetylcholine? Indirectly through microbiota on cortisol and serotonin hormones? The vagus nerve does not directly cause the microbiota to produce acetylcholine. However …
The Role of Serotonin and Cortisol
•
Microbiota influence on serotonin:
The gut microbiota affects tryptophan metabolism, a precursor to serotonin, and can produce serotonin itself, influencing the neurotransmitter levels in the body and brain.
•
Microbiota's impact on cortisol:
The microbiota-gut-brain axis is involved in regulating the stress response, which includes the production of hormones like cortisol.
How It Connects
a. Microbiota influence neurotransmitter levels: Gut bacteria influence the production of neurotransmitters like serotonin.
b. Vagus nerve activation by microbial products: These microbial products, including acetylcholine and others, can directly or indirectly activate the vagus nerve, which connects the gut to the brain.
c. Influence on hormonal regulation: The vagus nerve's signals influence brain regions that modulate mood, stress, and emotion, which are linked to hormones such as cortisol and serotonin.
d. Bidirectional communication: This creates a bidirectional relationship where the microbiota influences brain function via the vagus nerve, and brain activity also influences the gut microbiota.
Neurotransmitter modulation: The vagus nerve helps with stress management.
eleasante.com / le-lien-entre-le-nerf-vague-et-le-sommeil-implications-conséquences-et-pistes-thérapeutiques (in French) (The-link-between-the-vagus-nerve-and-sleep-implications-consequences-and-therapeutic-avenues)
When the vagus nerve is activated, it induces a state of relaxation and calms physiological stress reactions.
The vagus nerve modulates the production of cortisol via acetylcholine by promoting a state of relaxation and regulating the parasympathetic nervous system, which calms the body's stress response.
Acetylcholine, the main neurotransmitter of the vagus nerve, has anti-inflammatory effects too and improves mood, particularly nervous system activity, which is linked to increased cortisol production.
Music Use for Mood Regulation: Self-Awareness and Conscious Listening Choices in Young People with Tendencies to Depression.
https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2019.01199/full
Technique of Shavasana or Savasana
Vidéo (avancez jusque 45’’) : Relaxation et Pranayama - Viloma en Savasana
https://youtu.be/H4PJz-hFd54 (en français) 15’
=> You gradually and fairly slowly move through the contact points of the body parts in contact with the ground, starting from the head, i.e., the top of the skull.
You imagine that you are "exhaling" the load, the tension. You feel the tension, imagine the weight of the limbs, and you gradually release them, moving through the other limbs. You feel the weight of the body leaving you. Some people will not be able to directly use this technique until they have released excess stress through a fairly energy-intensive physical activity. Jogging, for example (or whatever physical activity suits you best).