The Wandering Nerve - research, work in progress.
Updated: May 28
Vagus nerve, also called X cranial nerve or 10th cranial nerve, longest and most complex of the cranial nerves. The vagus nerve runs from the brainthrough the face and thorax to the abdomen. It is a mixed nerve that contains parasympathetic fibres.
The vagus nerve has two sensory ganglia (masses of nerve tissue that transmit sensory impulses): the superior and the inferior ganglia. The branches of the superior ganglion innervate the skin in the concha of the ear. The inferior ganglion gives off two branches: the pharyngeal nerve and the superior laryngeal nerve. The recurrent laryngeal nerve branches from the vagus in the lower neck and upper thorax to innervate the muscles of the larynx (voice box). The vagus also gives off cardiac, esophageal, and pulmonary branches. In the abdomen the vagus innervates the greater part of the digestive tract and other abdominal viscera
A work in progress research blog entry with articles relating to the Vagus Nerve or the "wandering Nerve" and its correlation to psychological disorder that I feel are worth sharing among the BPD/mental health community here and on the private men's mental health group blog thing.
I am thinking this morning about this job I have taken on to try to learn how what happened to my mother when she was a little girl ended up turning her into the monster that tormented and traumatized me from the time I was born. Today the word ‘investigator’ rings in my thoughts. I think about accident investigators, criminal investigators, child protection investigators, and I think about myself as an investigator in the case of what happened to my mother.
Can we learn to tell the difference between child abuse that is a crime and child abuse that is an accident? Is the dividing line between the two really about conscious, wilful choice and intention? Where does ignorance fit into the picture? Negligence? Limitations due to very real disabilities?
What role does assigning blame, fault or accountability fit into the investigation of the causes and consequences of infant-child abuse, neglect and maltreatment or of any other accident, crime or trauma?
Obviously nothing can ever be done to change history, including my 18 year history with my mother. Yet it is one of the qualities of being human that allows us to both learn from history and then take what we learn to try to create a better future. Hindsight and foresight have been human allies for many, many thousands of years. While other animals are certainly capable of learning, of applying what they learned in the past to new situations in the future, it seems to be only our human species that can utilize one single, most important gift: Insight.
There will come a day in the future when I no longer concern myself with my forensic autobiographical investigative study about what happened to my mother. When that day comes, it will be because I have had my curiosity sated, because I gave up, or because I am dead. Today isn’t that day. Right now I am turning the light of my conscious investigation into the crime or the accident that was my mother’s entire approach to having me as her daughter. I am moving my search into a new direction. I want to know what my mother’s vagal nerve system had to do with the disaster that was her life, both as my mother and as a human being.
I posted the scanned images of Dr. Dacher Keltner’s chapter on compassion from his book, Born to Be Good: The Science of a Meaningful Life, on January 30, 2010. I am putting his words under my microscope today as I search specifically for what he says in this chapter about the vagal nerve system.
What, most simply, is the vagal nerve system? The WiseGeek states:
“The vagus nerve is either one of two cranial nerves which are extremely long, extending from the brain stem all the way to the viscera. The vagus nerves carry a wide assortment of signals to and from the brain, and they are responsible for a number of instinctive responses in the body. You may also hear the vagus nerve called Cranial Nerve X, as it is the 10th cranial nerve, or the Wandering Nerve. A great deal of research has been carried out on the vagus nerve, as it is a rather fascinating cranial nerve. Vagus is Latin for “wandering,” and it is an accurate description of this nerve, which emerges at the back of the skull and meanders in a leisurely way through the abdomen, with a number of branching nerves coming into contact with the heart, lungs, voicebox, stomach, and ears, among other body parts. The vagus nerve carries incoming information from the nervous system to the brain, providing information about what the body is doing, and it also transmits outgoing information which governs a range of reflex responses. The vagus nerve helps to regulate the heart beat, control muscle movement, keep a person breathing, and to transmit a variety of chemicals through the body. It is also responsible for keeping the digestive tract in working order, contracting the muscles of the stomach and intestines to help process food, and sending back information about what is being digested and what the body is getting out of it. When the vagus nerve is stimulated, the response is often a reduction in heart-rate or breathing. In some cases, excessive stimulation can cause someone to have what is known as a vaso-vagal response, appearing to fall into a faint or coma because his or her heart rate and blood pressure drop so much. Selective stimulation of this nerve is also used in some medical treatment; vagus stimulation appears to benefit people who suffer from depression, for example, and it is also sometimes used to treat epilepsy. Most of the time, you don’t notice the actions of the right and left vagus nerves, but you probably would notice if this nerve ceased to function as a result of disease or trauma, because the vagus nerve is one of the many vital nerves which keeps your body in working order. Without the functions of the vagus nerve, you would find it difficult to speak, breathe, or eat, and your heartbeat would become extremely irregular.”
While this might all sound very technical, medical and boring, I am trying to understand more about this wandering nerve system because there seems to be a major link between the Borderline Personality Disorder condition and changes in how this system works in a Borderline’s body. I posted the other day from a research study done by Austin, Riniola and Porges about Borderline’s and their vagal nerve system that concluded:
“The BPD group ended in a physiological state that supports the mobilization behaviours of fight and flight, while the control group ended in a physiological state that supports social engagement behaviors.“ (2007, Borderline personality disorder and emotion regulation: Insights from the Polyvagal Theory) This is NOT a minor or insignificant finding! There was something terribly wrong with my mother’s STOP and GO physiological process! As I begin to study about what might have been terribly wrong with her wandering vagal nerve system I begin to move from a consideration of how her brain-mind didn’t work right into the realization that her problem was probably much bigger: It was in her BODY as well. ++++ Turning to what Keltner says about compassion I see that he directly places the human ability to experience sympathy and compassion within the responses of this wandering vagal nerve system in our body. I’m not after hindsight or foresight right now. I’m after insight. What is this mysterious “bundle of nerves” and what might it have to do with my mother’s ability to traumatize little me?
Keltner states that this bundle, known as the vagus nerve: “…resides in the chest and, when activated, produces a feeling of spreading, liquid warmth in the chest and a lump in the throat. The vagus nerve…originates in the top of the spinal cord and then winds its way through the body…, connecting up to facial muscle tissue, muscles that are involved in vocalization, the heart, the lungs, the kidneys and liver, and the digestive organs. In a series of controversial papers, physiological psychologist Steve Porges has made the case that the vagus nerve is the nerve of compassion, the body’s caretaking organ.” (page 228 from Keltner’s book cited above) I notice that Porges is one of the researchers who accomplished the Borderline vagal nerve study I mentioned above. It seems that emotional information that would make a normal person’s Autonomic Nervous System’s (ANS) slow-down or STOP branch kick into gear instead had the reverse affect on these Borderlines. Their ANS-vagal nerve system not only did not slow down, it sped up into a GO state directly connected to fight/flight. Somehow, it seems, anything like a normal slow-down compassionate response was missing from their body-brain. While it’s true that “all that glitters is not gold,” these research findings more than make me think about my mother and her treatment of me! Her capacity to attack me was the opposite of normal! Think about the actions of any abuser you might know as you read what Keltner next writes about both Porges’ and his own work:
“…Porges notes that the vagus nerve innervates the muscle groups of communicative systems involved in caretaking – the facial musculature and vocal apparatus. In our research, for example, we have found that people systematically sigh – little quarter-second, breathy expressions of concern and understanding – when listening to another person describe an experience of suffering. The sigh is a primordial exhalation, calming the sigher’s flight/flight physiology, and a trigger of comfort and trust, our study found, in the speaker. When we sigh in soothing fashion, or reassure others in distress with our concerned gaze or oblique eyebrows, the vagus nerve is doing its work, stimulating the muscles of the throat, mouth, face, and tongue to emit soothing displays of concern and reassurance. “Second, the vagus nerve is the primary brake on our heart rate. Without activation of the vagus nerve, your heart would fire on average at about 115 beats per minute, instead of the more typical 72 beats per minute. The vagus nerve helps slow the heart rate down. When we are angry or fearful, our heart races, literally jumping five to ten beats per minute, distributing blood to various muscle groups, preparing the body for fight or flight. The vagus nerve does the opposite, reducing our heart rate to a more peaceful pace, enhancing the likelihood of gentle contact in close proximity with others. “Third, the vagus nerve is directly connected to rich networks of oxytocin receptors, those neuropeptides intimately involved in the experience of trust and love. As the vagus nerve fires, stimulating affiliative vocalizations and calmer cardiovascular physiology, presumably it triggers the release of oxytocin, sending signals of warmth, trust, and devotion throughout the brain and body, and ultimately, to other people. “Finally, the vagus nerve is unique to mammals. Reptilian autonomic nervous systems share the oldest portion of the vagus nerve with us, what is known as the dorsal vagal complex, responsible for immobilization behavior: for example, the shock response when physically traumatized; more speculatively, shame-related behavior when socially humiliated. Reptile’s autonomic nervous systems also include the sympathetic region of the autonomic nervous system involved in flight/flight behaviour. But as caretaking began to define a new class of species – mammals – a region of the nervous system, the vagus nerve, emerged evolutionarily to help support this new category of behavior.” (pages 229-230) ++++ As I read this information I think about Dr. Martin Teicher and his Harvard research group’s suggestion that infant-child abuse alters brain development toward one that is ‘evolutionarily altered’. As I combine this information with what Keltner just described I begin to think that it might be entirely possible that early infant-child maltreatment can alter the development of the vagal nerve system ‘evolutionarily altered’ ways, as well. I would doubt that these changes could possibly happen independently of one another. My bet is that if the brain is forced to change in its development in a malevolent early environment, the vagus nerve system is probably changed at the same time through similar processes of adaptation to trauma. Hence, if this is the case, the complete meltdown of my mother as a normal, healthy, happy woman! In fact, my investigative mind suspects that it is the operation of an infant-child’s vagus nerve system that collects the vital information – in its body — about the condition of the world the tiny one was born into that then feeds this information to the developing brain. As it turns out, the vagus nerve is directly tied to our immune system. I’ve often said that it seems completely logical to me that infant-child developmental changes in response to early trauma are an immune response to threat and toxic conditions within a malevolent environment that affect how our genes form in the body-brain during critical windows of growth and development. At the same time I realize that I live in a very brain-head-boss oriented culture, rather than in a vagus nerve-body-boss oriented culture. What if the real truth is that it is the information our vagus nerve collects from our body that signals our immune system to design our brain according to the conditions of our earliest environment from the start of our life?
This makes perfect sense to me. I am going to digress here for a moment and include some information from a completely different source that I believe fits into this picture I see being painted in front of me about how our vagus nerve might govern our most critical responses to our environment. I am referring to the writings of Daniel J. Levitin as he presents them in his 2007 book, This Is Your Brain on Music: The Science of a Human Obsession. Levitin is talking about the development of the human brain’s music system in relationship to our brain systems that support our speech:
“The close proximity of music and speech processing in the frontal and temporal lobes, and their partial overlap, suggests that those neural circuits that become recruited for music and language may start out life undifferentiated. Experience and normal development then differentiate the functions of what began as very similar neuronal populations. Consider that at a very early age, babies are thought to be synesthetic, to be unable to differentiate the input from the different senses, and to experience life and the world as a sort of psychedelic union of everything sensory. Babies may see the number five as red, taste cheddar cheeses in D-flat, and smell roses in triangles. “The process of maturation creates distinctions in the neural pathways as connections are cut or pruned. What may have started out as a neuron cluster that responded equally to sights, sound, taste, touch and smell becomes a specialized network. So, too, may music and speech have started in us all with the same neurobiological origins, in the same regions, and using the same specific neural networks. With increasing experience and exposure, the developing infant eventually creates dedicated pathways and dedicated language pathways. The pathways may share some common resources….” (pages 127-128)
When I apply my investigative thinking about how infant-child abuse, neglect, maltreatment and trauma changes body-brain development to both my mother and to myself, I am looking backwards in time at the impact of these malevolent experiences on the kinds of developmental processes that Levitin is describing here. These synesthetic experiences happen to us even before we are born, and most certainly happen within our infant body well before our nervous system-brain has finished development. I see no possible way that the vagus nerve cannot be centrally involved in these earliest stages of our development. All the information an infant’s body gathers from the conditions of its earliest caregiver interactions, that communicate to the growing body-brain either a safe and secure benevolent world or an unsafe and insecure malevolent world, would occur to a large extent through the vagus nerve system. I suspect that all this information is communicated to the immune system so that adjustments in development can be made as necessary.
Work in progress, I will publish as I go and structure it all later ......