The Heart's Little Brain!
The Heart's "Little Brain"
This week instead of dealing with an injury I thought I’d continue with a little known medical phenomenon and it really is brilliantly fascinating.
Recently researchers develop the first ever 3D map of the heart’s nervous system, providing a foundation for understanding the complexities of heart health and trying to understand more of what goes wrong. My were they surprised.
On the computer screen, a 3D model of a heart rotates seemingly in mid-air, a carousel of colours and contours. Amidst the blue and purple waves that denote the heart’s powerful muscles sit a cluster of yellow dots. To anyone else, it looks like a meaningless blob. But to |the researchers it represents a culmination of nearly three decades of work, a long-awaited key to a world of unanswered questions.
Let’s go back a bit: Thirty years ago, the scientific and medical communities were desperately trying to find answers for heart disease, which had become the single biggest cause of death in the Western World. Attention turned to a massive and meandering network of nerves called the Vagus Nerve, this carries signals from the brain, the master organ of our body, to other organs, including the heart. Scientists found that when these signals weren’t sent properly, it could actually impair heart health and even lead to heart failure. When they poked the Vagus Nerve with an electrode to help jump start it, they found that an ailing heart could actually pump better. It was a thrilling finding. But there was a problem, the scientists didn’t know where the Vagus Nerves ended in the heart, was it a certain chamber, or a muscle, or an electrical node? Which of these connections could explain how the Vagus Nerve affects heart health?
Around the same time in the early 1990’s researchers found that the heart had nerve cells or neurons that were akin to the ones that made up the brain. In other words, the heart had its very own nervous system that could function independently of the brain! Affectionately called “the little brain” of the heart it became a point of fascination in heart research. A million questions needed answers.
Why does the heart need its own nervous system anyway? How does it help the heart function? It also became a potential target for the Vagus Nerve. Could a connection between the brain and the “little brain” be the key to restoring heart health?
Dr. Schwaber and Dr. Vadigepalli have been at the forefront of trying to answer these questions
for the last 25 years, giving critical insight into the heart’s nervous system. In the last five years fate brought them together with other like-minded experts and cutting edge advanced technology that allowed a major breakthrough in Medical imaging. The first ever 3D map of the heart’s “little brain” was plotted, it is a map that gives an unprecedented look at not only how the neurons are organized in the heart, that strange blob of yellow dots, but also their biological properties. For the first time researchers are able to appreciate the spatial and functional relevance of the heart’s neurons in keeping the organ healthy, giving us new clues about how to tackle the longstanding issue of heart disease.
Researchers discovered that the Vagus Nerve connected to the Sinoatrial Node which controls heart rate. “That connection made sense for heart health,” says Dr. Schwaber. “But I wanted to know if the Vagus Nerve connected to the ventricles, the chambers that pump blood to the rest of the body. A connection here could be beneficial in understanding how to treat heart disease.”
To develop this further Dr. Schwaber turned to a molecular biologist by the name of Dr. Lynn Enquist who was developing a novel technique using a modified virus to label multiple relay points in a neural pathways. When Drs. Schwaber and Enquist injected the virus into the ventricles of a rat’s heart, they were able to trace the connections through the heart and all the way back to the neurons in the brain that gave rise to the Vagus Nerve. They had just shown that the Vagus Nerve does indeed connect directly to the working chambers and muscles in the heart.
So basically think of the heart as a control system, a bread-and-butter concept of engineering, control systems are all around us, the cruise control in your car that maintains a safe speed or the thermostat that works to keep your home at a preferred temperature, these systems work in such a way that when you change the information input, they can adjust to achieve the desired outcome.
The heart receives input from the brain about our internal state and environment, and it adjusts to maintain outputs like heart rate, blood pressure, etc. But the nerve fibers that were found going back into the heart’s ‘little brain’ resembled an internal loop that engineers call local controllers so what is this one adding to the control of the heart.
This became the basis of most of the heart research and it was found that when the internal loop was on, it could fine tune how the heart responds to signals from the brain. This improved the heart’s performance and made outputs like heart rate more reliable. When it was off, the heart’s “little brain” couldn’t correct local disturbances, and the external loop to the brain had to be recruited instead, making the control system less efficient. Without the internal loop playing this role of damage control, the heart could become erratic, leading to an irregular heartbeat or arrhythmia.
This work lead the way forward and heart research then started to incorporate brain research and further work on how the Vagus Nerve communicates. This had led to ground breaking research and treatment and is still driving research today.
But the story of the “little brain” doesn’t stop there, what about intuition, stress, and all the other emotions that our bodies deal with. Read on to understand how this develops and is managed in our bodies.
In each moment of every day, a conversation is taking place inside us. Without a doubt, it’s one of the most vital communications we will ever find ourselves engaged in. It’s the silent, often subconscious, and never-ending conversation of emotion-based signals between our hearts and our brains, also known as the heart brain connection.
The reason this conversation is so important is because the quality of the emotional signal our hearts sends to our brains determines what kind of chemicals our brains release into our bodies. When we feel what we would typically call negative emotions (for instance, anger, hate, jealousy, and rage), our hearts send a signal to our brains that mirrors our feelings. Such emotions are irregular and chaotic and this is precisely what the signal they send to the brain looks like. If you can picture a chart of the ups and downs of the stock market on a wild and volatile day you’ll have an idea of the kind of signals we create in our hearts in times of chaos.
The human body interprets this kind of signal as stress and triggers the mechanisms to help us respond appropriately. The stress from negative emotions increases the levels of cortisol and adrenaline, often called stress hormones, which prepare us for a quick and powerful reaction to whatever is causing us stress, the chemistry in our bloodstream changes, more commonly known as the fight-or-flight response. When we constantly trigger this response we program ourselves to respond in a particular way, creating habits that drive annoyed, frustrated and angry responses.
Conversely research has shown that when we create rejuvenating emotions, such as appreciation, care, gratitude, and compassion, the signal from heart to brain becomes more harmonized to reflect the quality of the emotions. In the presence of a harmonized signal, there is no need for the fight-or-flight response. The stress hormones decrease, allowing the heart and brain to shift and produce the chemistry that supports stronger immune response and greater amounts of DHEA, the precursor to all other hormones in the body.
Whether it’s based in emotions from stress or harmony, the conversation and connection between heart and brain, specifically, between the sensory neurites in our hearts and those that make up our brains, is constantly occurring it’s this conversation that creates the harmony of heart-brain connection and coherence described previously.
This is one of those places where science and spirituality overlap beautifully. While the science describes the electrical relationship and connection between the heart and the brain, ancient spiritual practices and techniques have helped people apply the relationship in their lives, and do so without a scientific explanation. Those of us who have practised meditation will understand the benefits and how our thinking and lives can change accordingly and all supposedly without a scientific explanation. Try it, you never know it may just work for you!