Summary: New research reveals the heart has its own complex nervous system, or “mini-brain,” capable of regulating the heartbeat independently of the brain. Conducted on zebrafish, the study identified specialized neurons within the heart, including some with pacemaker properties, challenging traditional views of heartbeat control.
This discovery provides new insights into heart diseases and potential treatments for conditions like arrhythmias. Researchers aim to explore how this cardiac nervous system interacts with the brain during stress, exercise, or disease to identify novel therapeutic targets.
Key Facts:
- The heart’s nervous system includes specialized neurons with pacemaker functions.
- This “mini-brain” regulates heartbeat independently of the central nervous system.
- Understanding it could lead to better treatments for heart diseases like arrhythmias.
Source: Karolinska Institute
New research from Karolinska Institutet and Columbia University shows that the heart has a mini-brain – its own nervous system that controls the heartbeat. A better understanding of this system, which is much more diverse and complex than previously thought, could lead to new treatments for heart diseases.
The study, conducted on zebrafish, is published in Nature Communications.
The heart has long been thought to be controlled solely by the autonomic nervous system, which transmits signals from the brain. The heart’s neural network, which is embedded in the superficial layers of the heart wall, has been considered a simple structure that relays the signals from the brain. However, recent research suggests that it has a more advanced function than that.
Controlling the heartbeat
Scientists have now discovered that the heart has its own complex nervous system that is crucial to controlling its rhythm.
“This ‘little brain’ has a key role in maintaining and controlling the heartbeat, similar to how the brain regulates rhythmic functions such as locomotion and breathing,” explains Konstantinos Ampatzis, principal researcher and docent at the Department of Neuroscience, Karolinska Institutet, Sweden, who led the study.
The researchers identified several types of neurons in the heart that have different functions, including a small group of neurons with pacemaker properties. The finding challenges the current view on how the heartbeat is controlled, which may have clinical implications.
Similar to the human heart
“We were surprised to see how complex the nervous system within the heart is,” says Konstantinos Ampatzis.
“Understanding this system better could lead to new insights into heart diseases and help develop new treatments for diseases such as arrhythmias.”
The study was conducted on zebrafish, an animal model that exhibits strong similarities to human heart rate and overall cardiac function. The researchers were able to map out the composition, organisation and function of neurons within the heart using a combination of methods such as single-cell RNA sequencing, anatomical studies and electrophysiological techniques.
New therapeutic targets
“We will now continue to investigate how the heart’s brain interacts with the actual brain to regulate heart functions under different conditions such as exercise, stress, or disease,” says Konstantinos Ampatzis.
“We aim to identify new therapeutic targets by examining how disruptions in the heart’s neuronal network contribute to different heart disorders.”
The study was done in close collaboration with researchers at Columbia University, USA, and was funded by, among others, the Dr. Margaretha Nilsson Foundation, Erik and Edith Fernström Foundation, StratNeuro and Karolinska Institutet. There are no reported conflicts of interest.
About this cardiovascular neuroscience research news
Author: Press Office
Source: Karolinska Institute
Contact: Press Office – Karolinska Institute
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Decoding the molecular, cellular, and functional heterogeneity of zebrafish intracardiac nervous system” by Konstantinos Ampatzis et al. Nature Communications
Abstract
Decoding the molecular, cellular, and functional heterogeneity of zebrafish intracardiac nervous system
The proper functioning of the heart relies on the intricate interplay between the central nervous system and the local neuronal networks within the heart itself.
While the central innervation of the heart has been extensively studied, the organization and functionality of the intracardiac nervous system (IcNS) remain largely unexplored.
Here, we present a comprehensive taxonomy of the IcNS, utilizing single-cell RNA sequencing, anatomical studies, and electrophysiological techniques.
Our findings reveal a diverse array of neuronal types within the IcNS, exceeding previous expectations. We identify a subset of neurons exhibiting characteristics akin to pacemaker/rhythmogenic neurons similar to those found in Central Pattern Generator networks of the central nervous system.
Our results underscore the heterogeneity within the IcNS and its key role in regulating the heart’s rhythmic functionality.
The classification and characterization of the IcNS presented here serve as a valuable resource for further exploration into the mechanisms underlying heart functionality and the pathophysiology of associated cardiac disorders.
