New research from Karolinska Institutet in Sweden and Columbia University in the United States has revealed something surprising about the heart: it has its own “mini-brain.”
This discovery could change how we understand and treat heart diseases in the future.
For a long time, scientists believed that the brain was solely responsible for controlling the heartbeat through signals sent by the autonomic nervous system. This system is like a communication highway from the brain to the organs.
The heart was thought to be a simple receiver of these signals, with a basic nerve structure that just followed the brain’s instructions.
However, the new study shows that the heart has its own complex nervous system, located in the outer layers of the heart wall. This network of neurons, or nerve cells, can help control the heartbeat on its own.
Dr. Konstantinos Ampatzis, the lead researcher from Karolinska Institutet’s Department of Neuroscience, explains that this “little brain” inside the heart plays a key role in keeping the heartbeat steady. It’s similar to how the brain controls rhythmic activities like breathing or walking.
The study was done on zebrafish, a small fish often used in medical research because its heart functions similarly to the human heart. Using advanced tools like single-cell RNA sequencing and electrical recordings, the scientists mapped out the different types of neurons in the heart.
They found several types of nerve cells, each with its own role. One small group of these neurons even had pacemaker-like properties, meaning they help start and regulate the heartbeat.
These results challenge the older belief that the heart is just a passive organ controlled by the brain. Instead, it appears that the heart has its own active system that helps manage its rhythm. This deeper understanding of how the heart works could open the door to new treatments for heart rhythm disorders, such as arrhythmias.
Dr. Ampatzis says the complexity of the heart’s nervous system was unexpected. The team now plans to study how the heart’s mini-brain works together with the brain, especially during physical activity, stress, or illness. They hope to learn how this system breaks down in heart disease and to find new targets for therapies.
The research was a collaboration between scientists in Sweden and the U.S. It was funded by several foundations, including the Dr. Margaretha Nilsson Foundation and the Erik and Edith Fernström Foundation, and supported by Karolinska Institutet. There were no reported conflicts of interest.
This exciting discovery adds a new layer to our understanding of how the body works. It shows that even the heart, often seen as just a muscle pump, has its own intelligence and control system. As research continues, this knowledge could help millions of people with heart problems live healthier lives.
If you care about heart disease, please read studies that herbal supplements could harm your heart rhythm, and how eating eggs can help reduce heart disease risk.
For more health information, please see recent studies that apple juice could benefit your heart health, and results showing yogurt may help lower the death risks in heart disease.
The study is published in Nature Communications.
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