How Trauma Gets Trapped in Your Body: Understanding the Vagus Nerve (Part 1)

This episode, the first in a three-part series, introduces the vagus nerve as a crucial family of neural pathways acting as the body's primary messenger system, transmitting information both to and from the brain. It highlights the vagus nerve's extensive connections to nearly all bodily systems, including the heart, gut, liver, spleen, kidneys, and digestive system. A key piece of evidence for its importance is a rat study demonstrating that while altering the gut microbiome affected behavior in rats with intact vagus nerves, it had no effect on those with severed vagus nerves, underscoring the nerve's role in the gut-brain axis.

The podcast details the vagus nerve's involvement in the orienting reflex, which is the body's automatic response to environmental changes. It explains how the vagus nerve mediates the physiological stress response, triggering the HPA axis and initiating fight-or-flight reactions. This includes increased heart rate, rapid breathing, and significant changes in gut function, often leading to symptoms like Irritable Bowel Syndrome (IBS), flatulence, and diarrhea during anxiety. The episode also explores the vagus nerve's connection to the trigeminal nerve, which innervates the face, showing how facial expressions like scowling or smiling communicate with the vagus nerve and influence the body's internal state.

Furthermore, the discussion delves into the auricular branches of the vagus nerve located in the ear. Stimulating these points, through methods like massage or TENS units (to be discussed in part three), is theorized to activate the 'rest and digest' parasympathetic response. This provides an initial glimpse into practical applications for regulating the vagus nerve, emphasizing that its widespread innervation means its dysfunction can manifest in a variety of physical symptoms throughout the body.

Finally, the episode connects the vagus nerve directly to trauma, explaining how past traumatic experiences create 'schema' or shortcuts in the brain. When sensory organs detect triggers associated with these traumas, the vagus nerve relays this information to the brain, activating the 'default mode network' and initiating a stress response. The host briefly introduces the concept of recalibrating the vagus nerve and orienting reflex by learning to deactivate this 'autopilot' and engage the 'executive control network' for higher-order thinking, allowing individuals to assess current safety despite past experiences.

the vagus nerve is actually a family of neural pathways that carry information both to and from the brain

I think of it kind of like the body's email system or messenger system

when they had rats that had their vagus nerves severed altering the gut microbiome did not affect their behavior but in rats in which the vagus nerve was still intact alterations in the gut microbiome actually produced alterations in behavior

the vagus nerve can also trigger what's called the orienting reflex

when that hpa axis gets kicked off the vagus nerve tells all of those organs hey threat warning fight or flee

when people get anxious they tend to have more ibs more um irritable bowel more flatulence more diarrhea

when you smile your maxillary zone uh areas of the trigeminal nerve are are triggered and that tells the vagus nerve hey this person is smiling so there must be something positive going on

massaging there kind of under where your ear rolls if you want to call it massaging there and then inside in the concave area of your ear there are also other points and then on what's called the tragus which is the little flap of skin that covers your ear hole for lack of a better word that is also innervated

when you experience trauma the brain learns from that and creates what we've called called in other videos schema or shortcuts about when this situation occurs it's a threat

one of the tricks that is important or tools I guess that's important for recalibrating the vagus nerve and the orienting reflex is to help the person learn how to deactivate that autopilot and activate what they call the executive control network