The vagus nerve is the tenth cranial nerve and is the longest in the body. It is a large meandering nerve with numerous branches and gets its name from wandering like a vagabond.
The vagus nerve communicates with every organ in the body and oversees a range of vital functions. It passes through the gut, lungs, diaphragm, throat, inner ear, and facial muscles. It also controls our inner nerve centre and the parasympathetic nervous system, allowing for the regulation of our survival responses when faced with danger and threat.
Our ever-vigilant sympathetic nervous system activates our fight or flight response which floods the body with the stress hormones cortisol and adrenaline. The vagus nerve counteracts this evolutionary response by releasing the neurotransmitter acetylcholine and enzymes and proteins such as prolactin, vasopressin, and oxytocin, which all help promote calm and relaxation. Those with a strong and healthy vagus response are more likely to recover promptly from stress, injury, or illness.
Recent research demonstrates it is the missing link to treating trauma, anxiety disorders, and chronic inflammation, and can alleviate symptoms for numerous medical conditions.
Here are five facts about the vagus nerve you might not be aware of:
1. It Prevents Inflammation
Inflammation is a normal reaction to injury or illness. It is normally a local and temporary reaction which upon resolution, sees physiological and immune homeostasis restored. However, this natural inflammation response can be disrupted and result in persistent pro-inflammatory cytokine activity, which leads to excessive or chronic inflammation.[1] Chronic inflammation underlies a range of medical syndromes, including rheumatoid arthritis, sepsis, auto-immune diseases, and inflammatory bowel disease.
The vagus nerve assists in preventing or neutralising these pro-inflammatory responses. Its positioning throughout the body’s major organs alerts the brain to the presence of these cytokines and, in response, produces anti-inflammatory neurotransmitters that regulate our immune response.
Numerous studies have evidenced that stimulating the vagus nerve significantly reduces inflammation. Implanted nerve activators have been used to motivate the vagus nerve which showed a drastic reduction, and even remission, in sufferers of rheumatoid arthritis, haemorrhagic shock, and other inflammatory syndromes.[2]
2. It Creates Memories
The vagus nerve helps with the formation of memories. It carries sensory messages to and from the brain, and through the release of the powerful neurotransmitter norepinephrine into the brain’s amygdala region, memory formation and storage is strengthened. Norepinephrine additionally regulates arousal and feeling responses to emotional stimuli meaning that memories are rich and clear.[3]
A healthy vagus nerve can not only help with creating positive memories it can also assist in coping with traumatic flashbacks or intrusive thoughts.
Recent studies have found that a regulated vagus nerve can alleviate cognitive functions in many neuropsychiatric conditions, including Alzheimer’s disease.[4]
3. It Assists With Breathing
The vagus nerve directs your lungs to breathe through the activation of the neurotransmitter acetylcholine. This neurotransmitter is not only essential for our survival and for promoting beneficial oxygen levels in the blood and organs; it also promotes relaxation.
Those suffering from anxiety, stress, or trauma disorders such as PTSD remain on high alert, resulting in an inefficient release of acetylcholine and an inability to return to homeostasis. Building a strong mind and body connection with the vagus nerve will allow the body to relax and release trapped energy.
You can stimulate this vagus nerve response through breathing deeply. Taking regular deep breaths immediately relaxes the body as the vagus nerve can turn off the autonomic nervous systems fight or flight response which triggers the stress hormones cortisol and adrenaline.
4. It Controls Heart Rate
The vagus nerve controls heart rate through electrical impulses into specialised muscle and heart tissue. Acting as the body’s natural pacemaker, heart rate will be elevated when faced with a threat in order to prime the body for fight or flight, and the previously mentioned acetylcholine is vital for slowing the pace once the threat has passed.
The vagus nerve can also cause heart rate and blood pressure to drop when experiencing stress; this is known as vagal syncope. This is commonly experienced in those with phobias such as needles, the sight of blood, or flying, and a person may become weak, dizzy, or lose consciousness and faint.[5]
5. It Initiates Relaxation
As we have discovered, the vagus nerve is key to our fight-flight-freeze response through its connection to the parasympathetic nervous system. This response triggers a high level of stress responses within the body, and if the vagus nerve mind-body connection is strong, the body can return to a state of calm homeostasis once the threat has passed.
The vagus nerve has two components that become activated during the flight-fight response:
- The dorsal branch of the vagus nerve triggers our freeze response. This can cause tonic immobility, motor inhibition, and a general slowing down of bodily functions.
- The ventral branch stimulates the rest and digest response, lowering stress and returning our body to calm.
These responses are often involuntary and subconscious, relating to our past experiences and perceptions of threat. The polyvagal theory, discovered by Dr Stephen Porges, proposes that the strengthening of the vagus nerve leads to the ventral vagal state in the ventral branch. This promotes calm, a sense of safety, positive connection to others, and allows for personal growth and freedom from triggers.
Conclusion
This fascinating nerve is a powerful tool in negotiating life’s challenges and adversities to help reduce stress and live a calm and positive life.
We can all work on naturally stimulating our vagus nerve with somatic experiencing techniques such as practicing mindful body awareness, altering the rhythm of our breath, and exploring yoga and gentle movement to create a greater connection between body and mind.
If you have a client or know of someone struggling with anything you have read in this blog, reach out to us at Khiron Clinics. We believe that we can improve therapeutic outcomes and avoid misdiagnosis by providing an effective residential program and outpatient therapies addressing underlying psychological trauma. Allow us to help you find the path to realistic, long-lasting recovery. For more information, call us today. UK: 020 3811 2575 (24 hours). USA: (866) 801 6184 (24 hours).
Sources:
[1] Pavlov, Valentin A., and Kevin J. Tracey. “The Vagus Nerve And The Inflammatory Reflex—Linking Immunity And Metabolism”. Nature Reviews Endocrinology, vol 8, no. 12, 2012, pp. 743-754. Springer Science And Business Media LLC, doi:10.1038/nrendo.2012.189. Accessed 16 Oct 2021.
[2] Koopman, F. A., Chavan, S. S., Miljko, S., Grazio, S., Sokolovic, S., Schuurman, P. R., et al. (2016). Vagus nerve stimulation inhibits cytokine production and attenuates disease severity in rheumatoid arthritis. Proc. Natl. Acad. Sci. U.S.A. 113, 8284–8289. doi: 10.1073/pnas.1605635113
[3] ADELSON, RACHEL. “Stimulating The Vagus Nerve: Memories Are Made Of This”. Https://Www.Apa.Org, 2011, https://www.apa.org/monitor/apr04/vagus.
[4] Chang, Chun-Hung et al. “Brain Stimulation In Alzheimer’s Disease”. Frontiers In Psychiatry, vol 9, 2018. Frontiers Media SA, doi:10.3389/fpsyt.2018.00201. Accessed 16 Oct 2021.
[5] Jeanmonod R, Sahni D, Silberman M. Vasovagal Episode. [Updated 2021 Oct 7]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470277/