The Enteric Nervous System
BRAIN VS BODY: BODIES OUT OF BALANCE
As human animals we’re born as bodies with big powerful brains sitting up top in our heads. Our culture teaches us to value what goes on in the brain over what takes place in the rest of the body. Many of us learn to believe information generated by our brains and more or less ignore information available from the rest of the body – until something goes wrong down there.
And there’s so much that can go wrong from this disconnected, out of balance way of living. We then see a doctor to try to fix the symptoms of our ailment with medicines or surgery.
The way too many of us live – staying mostly up in our heads with little idea of our feelings and our true needs, all information generated by our guts:
Living Up In Your Brain – Relying Too Much on Thinking
The way we’re meant to be – brain and gut connected in constant communication:
The Gut and Brain Need to Interact for Good Physical and Mental Health
The human gastrointestinal tract:
YOU HAVE TWO BRAINS – ONE RESIDES IN YOUR HEAD AND ANOTHER VERY IMPORTANT ONE LIVES IN YOUR GUT
We’re used to thinking of the brain in the head as the body part that’s running the show but, in fact, we also have a second brain. It resides in our digestive tract.
Parts of the enteric nervous system (the gut brain) and their functions:
A BRIEF COURSE ON OUR TWO BRAINS (Hardin, 2014 A-C)
On average, the human brain, the seat of all our thinking, contains 86 billion neurons engaged in transmitting information to and from the rest of the body.
The human enteric nervous system (the gut) contains 100 million neurons – about 1000th the number in the human brain and about equal to the number in the human spinal cord.
The autonomous nervous system of the gut allows it to work independently of the brain.
Our guts make more independent decisions for us than any other part of the body.
The gut’s endocrine signaling to the entire body is quite elaborate. Communication from our gut-dwelling microbes to the brain affects our emotions, motivation, cognition, memory and behavior.
Just like our thinking brain, our gut brain is also able to learn and remember.
In the lowest, most primitive part of our brains, a neural network called the basal ganglia is constantly evaluating the outcomes of our every behavior, extracting decision rules: ‘When I said that, it worked out well.’ ‘When I did this, bad things happened.’ And so on, like a tireless experimental scientist tasked with guiding us wisely through our lives.
The basal ganglia in the brain store our accumulated life wisdom. But when we are faced with a decision, it is the brain’s verbal cortex that delivers our thoughts about it, often drowning out the wisdom accumulated inside the basal ganglia’s storehouse.
And the most interesting part: The basal ganglia area is so primitive it has NO CONNECTION to the verbal cortex so it can’t share its knowledge in words – but its connections to the gut are plentiful. The basal ganglia area tells us what is right or wrong for us as a GUT FEELING.
So trust your gut, your felt sense, your intuition – not what comes to you in words from your brain!
Nearly every brain-regulating chemical found in our skull brains is also found in our gut brains. This includes major neurotransmitters (serotonin, dopamine, glutamate, norepinephrine and nitric oxide), brain proteins called neuropeptides, major immune system cells, a class of the body’s natural opiates (enkephalins), and even benzodiazepines (the family of psychoactive chemicals found in drugs such as Valium and Xanax).
The gut has opiate receptors much like the brain. Drugs such as morphine and heroin attach to opiate receptors in the brain and also in the gut, causing constipation. Both brains can be addicted to opiates.
Our emotions are greatly influenced by chemicals and nerves inside the gut. Most of us know Prozac as a best selling anti-depressant pharmaceutical. In 1971, when Eli Lilly was developing the drug, they expected it would become a treatment for high blood pressure or obesity.
Prozac works by increasing brain levels of serotonin, a neurotransmitter that produces feelings of well-being. Serotonin also affects sleep, appetite and aggression.
Known side effects of Prozac include nausea, diarrhea, insomnia, and a lowered sex drive – clear evidence of a gut-brain interaction.
90% of the body’s serotonin is located in the gut, where it regulates intestinal movements. Only 10% is synthesized in the central nervous system, where it serves many functions – including mood regulation, appetite, sleep, and the cognitive functions of memory and learning.
I’ve noticed as a psychotherapist that people’s voices relax and become lower pitched when they’re speaking their gut truths and get tenser and higher pitched when they’re saying what they think.
I can’t tell you the number of times I’ve asked somehow how they feel about something and am instead told how they think they feel. Not so useful.
Makes you realize how important it is for those two brains to communicate with each other – and how mistaken we are when we look to the brain in the head to tell us how we feel and what we need As Joan Rivers always said:
So how can you improve the communication between your gut and your brain? Here’s an exercise to try. STAIRCASE EXERCISE To help you spend less time in your head and more time in your body – and find it easier to go back and forth between them
Picture a lovely old circular stone staircase, maybe one winding down inside a medieval castle tower.
Imagine the top of the staircase is the brain up in your skull. Its steps lead down to the GI tract down in your gut.
Stand quietly for a moment up at the top of the staircase breathing slowly, letting your eyes look down a few steps. What color are they? What kind of texture do they have
Notice the old stones the make up the stairs and walls. What color are they? What kind of texture do they have?
What’s the quality of the light inside the staircase?
Is it quiet in this staircase?
What emotions do you feel?
What bodily sensations do you notice?
Slowly step down to the second stair. Stand there a moment, breathing slowly and deeply, looking around.
Slowly step down to the third stair. Stand there a moment, breathing slowly and deeply, looking around.
Continue slowly down the other stairs, pausing between breaths on each stair.
If you can’t pause between breaths yet, rest for a few breaths on each stair before moving on.
Slowly descend the whole staircase in this manner observing what you see and what you’re feeling along the way, emotionally and sensations in your body.
When you reach the bottom of the staircase, spend a few easy breaths down there, in your gut. What do you see down there? What sensations do you feel?
When you’re ready, turn around and slowly walk back up the staircase to your brain in this same manner, noting what you see and how you’re feeling along the way.
When you reach your brain again, spend a few easy breaths up there. What do you see up there? What sensations do you feel?
Do you notice anything that’s different from the last time you were up there at the start of this walk? How’s your breathing?
Don’t worry if you’re unable to move down from the top step when you first try this exercise. Can you let yourself just be where you are on your staircase, breathing and looking around? Without chastising yourself?
Eventually, you’ll find you’re able to move further down toward your gut, which will be happy to greet you whenever you arrive.
REFERENCES Hardin, J.R. (2014-A). Intriguing Facts About the Gut and Brain. AllergiesAndYourGut.com. See: https://www.allergiesandyourgut.com/post/intriguing-facts-about-the-gut-and-brain
Hardin, J.R. (2014-B). Our Second Brain – The Gut Mind. AllergiesAndYourGut.com. See: https://www.allergiesandyourgut.com/post/our-second-brain-the-gut-mind
Hardin, J.R. (2014-C). The Gut Microbiome – Our Second Genome. AllergiesAndYourGut.com. See: https://www.allergiesandyourgut.com/post/the-gut-microbiome-our-second-genome
© Copyright 2014 Joan Rothchild Hardin. All Rights Reserved.
DISCLAIMER: Nothing on this site or blog is intended to provide medical advice, diagnosis or treatment.
Comments submitted prior to 8/25/2021
This exercise is intriguing. It might be good to introduce into our clinical work, as appropriate, of course. I’ll keep it in mind. Thanks for taking the time to write this, as always!
Thanks, Sonnische. I developed the staircase exercise for some of my patients who spend a lot of time in their heads and have trouble getting down to the emotional knowledge in their guts. If you use it, please let me know how it goes and any tweaks you or your patients make to it.
Hey Joan. Came across your article and loved it. Have been studying something of a similar nature and what you say about the second brain is right on. Turns out that we also have another brain. Have you heard about the heart brain in your travels? Not only can we communicate to the gut we can also have similar conversations with the heart brain.
In reply to Bill.
Thanks for this comment, Bill. Yes indeed – the heart’s information processing functions and its communication with the rest of the body are quite interesting. I suspect we’re also going to find there are several other ‘brains’ located in our bodies. Eg, the web of fascia around and in our muscles and organs is vast, all connected and loaded with nerves. Fascia is a liquid crystal matrix and communication throughout this system occurs even more quickly than in the nervous system. Just last week, two people brought this to my attention:
It turns out that when our fingertips touch something, the sensory information is processed there locally and the synthesized information, not the raw data, is sent to the brain. Very interesting. I’ve ordered a book called The Hand: How Its Use Shapes the Brain, Language, and Human Culture (Frank R. Wilson, 1999) to find out more about how this works.