Neural Inhibition: Implications for Chronic Pain and Anxiety
- Aug 14, 2023
- 6 min read
Updated: Sep 5, 2023
Neural Inhibition and the Vagus Nerve
The nervous system consistently fluctuates between states of "facilitation" and "inhibition". In a normally functioning individual, the nervous system is never totally "on" or totally "off". It must be able to transmit sufficient neurological signals in order to get things done (facilitation), but it must also be able to counteract that excitation by dialing those signals down (inhibition). Facilitation or excitation of the nervous system is accomplished by the sympathetic nervous system, the "fight-or-flight" nervous system. This is the "dial-it-up" nervous system, as it prepares you for action. Conversely, the parasympathetic nervous system is your "dial-it-down" and inhibit nervous system. This part of the nervous system is responsible for rest, recovery, digestion, and calming and is controlled by the vagus nerve. This nerve originates in the brain, runs through the neck, in close proximity to all of the important blood vessels that are allowing blood supply to and from the brain, and enters the abdomen, where it exerts control over all of your vital body organs and functions.
Inhibition, Pain, and Anxiety
As stated, in a healthy nervous system, the body fluctuates easily between needed levels of facilitation versus needed levels of inhibition. If you are walking across the street and a car is barreling toward you at 50 mph, your nervous system better be able to dial-up the facilitation! But by the end of the day, the body will then need to dial down excitation and cause inhibition, or you will not have much luck in getting to sleep! Sometimes, though, we experience states where either facilitation or inhibition dominates for longer periods of time than is ideal or functional. Anxiety and chronic pain are examples in which facilitation dominates the nervous system. This is why when an individual is anxious, they get "antsy" and have difficulty relaxing or sleeping, and why pain gets "ramped up" even when activity has not warranted that response. Depression and chronic fatigue are examples of states in which inhibition dominates. This explains why when an individual is depressed or fatigued, they have difficulty standing up straight and tend to move much more slowly.
For many of us, the majority of the time, inhibition and facilitation occur in the perfect balance that is necessary for our body to function ideally, but with conditions like chronic pain, anxiety, chronic fatigue, and depression, this process of moving back and forth fluidly between facilitation and inhibition gets dysregulated. Even those of us who are not dealing with chronic health conditions find ourselves sometimes at places in which we are dealing with a preponderance of one or the other (Being stressed at work for the month because of having to meet a deadline likely means you are living more chronically in the "facilitation mode").
Regardless of whether we are dealing with chronic conditions like Chronic Pain or Anxiety, all of us can benefit from an understanding of the way in which the nervous system works and what factors might be likely to produce a desired neurological response. Thankfully, there are many things that we can do to promote inhibition, or "turning down the excitation" of the nervous system (as well as for increasing facilitation, but that is the subject of another blog!) Being able to regulate the nervous system and "dial down" or inhibit our sympathetic nervous system is associated with many positive health outcomes! So keep reading to discover some ideas for doing so!
Neurotransmitters and Inhibition-Facilitation
Inhibition and facilitation of the nervous system are controlled by two main neurotransmitters. All neurotransmitters tell nerve cells whether to fire or not. A facilitatory neurotransmitter gives the signal to fire and an inhibitory neurotransmitter gives the signal to stop firing. GABA is the nervous system's primary inhibitory neurotransmitter. Glutamate is the nervous system's primary facilitatory neurotransmitter. These two neurotransmitters must remain in balance in order for our body to function effectively. Interestingly enough, Glutamate is the precursor to GABA. In other words, the nervous system attempts to prevent too much facilitation by converting Glutamate into the body's main inhibitory neurotransmitter, GABA.
There are dietary means and supplemental means of addressing dysregulation (or imbalance) of these neurotransmitters, but that is not the focus of this post (and using these strategies should always occur under the supervision of a clinical specialist). As an interesting aside, however, glutamate is converted to GABA with the help of vitamin B6! Vitamin B6 has even been recognized in the research as a helpful adjunct in regulating the nervous system for individuals tapering off of "benzos" (a class of drug which promotes excessive "inhibition" and is now recognized as potentially causing significant dysregulation with long-term use), as well as for individuals experiencing dysregulation in the form of anxiety and depression.
Yoga and Slow, Sustained Stretching
Most individuals have heard of the benefit of yoga and stretching in respect to improved flexibility and strength. Many people have also heard that yoga is a great form of relaxation or stress management because it couples mindfulness with deep breathing. We know from research that deep breathing, mindfulness , and the slow-sustained stretches which occur with the practice of yoga, promote a parasympathetic response in the nervous system. This response is necessary for rest, relaxation, digestion and recovery. This response calms us and counteracts our "fight or flight stress response." Yoga is a great way of promoting a parasympathetic response.
More traditional stretching is also a great way to promote inhibition. This should always be conducted slowly when the desired response is inhibition (and in order to prevent injury!) Rapid stretching actually kicks in a reflex that promotes facilitation of the muscle you are trying to stretch, and can easily cause injury! When stretches (including yoga stretches) are completed slowly, the nervous system must shut down activation of that muscle in order to allow it to elongate or stretch. In other words, you cannot easily stretch a muscle that the nervous system has not relaxed or inhibited. That means that spending some time working on stretching the body, either through engagement in yoga or traditional stretching, is also helping the nervous system regulate and calm down!!
Rotation, Rocking and Inhibition
Rotation of the trunk or the limbs also has an inhibitory effect on the nervous system. In order for any part of our body to move, the brain must facilitate one muscle group (the one that is moving the body part) and at the same time, inhibit the opposing muscle group (the one that performs the opposite motion). Otherwise, the opposing muscle group would be fighting the movement. For example, the biceps is the muscle that allows one to do "biceps curls"; however, in order to perform a curl, the triceps (which straightens the elbow) must be inhibited. Because rotation of a limb or trunk includes rapid reversal of movement in so many planes, and consists of small degrees of multiple opposing movements, the brain's overall response to rotation is greater inhibition than facilitation. Rocking is very similar to rotation, as it is comprised of slow, rhythmic reversals in movement direction. Think about the effect that rocking and rotation have on a crying baby. These are strategies used to soothe infants, because they are naturally calming, or inhibitory to the nervous system.
Mindfulness and Inhibition
If you are interested in learning about Mindfulness: what it is and how it can help the nervous system regulate, check out our latest post!
Diaphragmatic Breathing and Inhibition
Diaphragmatic breathing is a practice which focuses on slow, mindful attention to one's breathing. Diaphragmatic breathing emphasizes expansion of the belly with inspiration, like a balloon, and flattening of the chest and diaphragm with exhalation. This type of breathing stimulates the vagus/vagal nerve, the major "inhibitory" controller of the nervous system.
Deep Pressure/Massage and Inhibition
Deep pressure, such as that which is applied in many manual interventions such as massage, is generally inhibitory to the nervous system. Deep pressure in the form of weighted blankets, etc., are also used as an inhibitory and regulatory technique for individuals with autism, anxiety and insomnia.
If you are interested in exploring how using the inhibitory and regulatory techniques discussed in this post might help you manage your chronic pain or other chronic condition, come join us in our virtual Mindful Movement education and movement class, Thursdays at 3:30 pm, EST and click the following:
Effects of yoga on the autonomic nervous system, gamma-aminobutyric-acid, and allostasis in epilepsy, depression, and post-traumatic stress disorder https://pubmed.ncbi.nlm.nih.gov/22365651/
Vitamin B6: A new approach to lowering anxiety, and depression? ttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC9577631/
How to Increase GABA and Balance Glutamate
Help for dysregulation tied to fibromyalgia and chronic fatigue symptoms https://www.verywellhealth.com/treating-gaba-and-glutamate-dysregulation-716040
Weighted Blanket Use: A Systematic Review https://pubmed.ncbi.nlm.nih.gov/32204779/
A weighted blanket increases pre-sleep salivary concentrations of melatonin in young, healthy adults https://pubmed.ncbi.nlm.nih.gov/36184925/
Effects of voluntary slow breathing on heart rate and heart rate variability: A systematic review and a meta-analysis https://pubmed.ncbi.nlm.nih.gov/35623448/ (Watch for our upcoming post on heart rate variability!)
Disclaimer: This BLOG is for Educational Purposes, Only. This information provided is educational and informational in nature and is made only as general information. The information does not establish a patient-provider relationship, establish a standard of care, or offer medical, dietary, or therapeutic care, advice, opinion, diagnosis, or treatment. This information does not replace independent professional or medical judgment and should not be relied upon as medical, psychological, or other professional advice of any kind or nature whatsoever. This information should not be used for diagnosing or treating any mental or physical health problem or disease. You are solely responsible for any action taken based on your interpretation of this information and you are responsible for your own health care decision-making by obtaining any necessary consultations with appropriately licensed health care professionals such as physicians and psychologists.
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