New studies reveal that the heart features a miniature brain—a dedicated nervous system responsible for managing its heartbeat. Gaining a deeper understanding of this system, which is more intricate and varied than previously believed, could pave the way for innovative treatments for heart ailments.
Recent investigations by the Karolinska Institutet and Columbia University have unveiled that the heart possesses a mini-brain—its very own nervous system that regulates the heartbeat. A more detailed comprehension of this system, which is significantly more elaborate than earlier assumptions, could lead to new therapeutic options for heart diseases. This research, performed on zebrafish, is detailed in Nature Communications.
Traditionally, it was assumed that the heart operated only under the control of the autonomic nervous system, which sends signals from the brain. The heart’s neural network, located within the outer layers of the heart’s wall, was thought to be a simple conduit for these signals. However, recent findings indicate that the heart’s neural system is far more complex.
Managing the heartbeat
Researchers have uncovered that the heart has its own intricate nervous system that plays a crucial role in regulating its rhythmic contractions.
“This ‘little brain’ is vital for sustaining and orchestrating the heartbeat, much like how the brain governs rhythmic activities such as walking and breathing,” says Konstantinos Ampatzis, the lead researcher and docent at the Department of Neuroscience at Karolinska Institutet, Sweden.
The team identified various types of neurons within the heart, each serving distinct purposes, including a small group of neurons with pacemaker characteristics. This discovery questions the established understanding of heart rhythm regulation, which could have significant clinical implications.
Similar to the human heart
“We were astonished by the complexity of the heart’s nervous system,” notes Konstantinos Ampatzis. “Gaining a better understanding of this system could provide new insights into heart diseases and aid in creating novel treatments for conditions like arrhythmias.”
The research utilized zebrafish, an animal model that closely mirrors human heart rate and overall cardiac functionality. By employing a combination of techniques, including single-cell RNA sequencing, anatomical examination, and electrophysiological analysis, the researchers were able to map and explore the structure, organization, and roles of neurons within the heart.
New targets for therapy
“We are now poised to further explore how the brain’s connection with the heart influences cardiac functions under various circumstances, such as exercising, stress, or illness,” states Konstantinos Ampatzis. “Our goal is to identify new therapeutic targets by investigating how disturbances in the heart’s nerve network contribute to various heart conditions.”
This study was a collaborative effort with researchers at Columbia University, USA and was funded by organizations including the Dr. Margaretha Nilsson Foundation, the Erik and Edith Fernström Foundation, StratNeuro, and Karolinska Institutet. There are no declared conflicts of interest.