New research from Karolinska Institutet and Columbia University has revealed an unprecedented discovery: The heart has its own nervous system, often called the nervous system. The “miniature brain,” which plays an important role in controlling the rhythm of the heartbeat.

The study, published in Nature Communications, challenges the long-held belief that the heart is controlled entirely by signals coming from the brain through the autonomic nervous system.

Traditionally, the neural network of the heart was considered a simple relay system, simply transmitting commands from the brain.

However, researchers have now identified a complex network of neurons embedded within the heart wall that significantly contribute to maintaining and regulating the heartbeat.

“This ‘little brain’ has an important role in controlling the heartbeat, just as the brain controls functions such as movement and breathing,” explained lead researcher Constantinos Ampatzis of Karolinska Institutet.

The team conducted their study using zebrafish, which are an ideal model because of their physical similarity to humans.

They discovered different types of neurons within the heart, including a specific group with pacemaker properties that directly influence heart rhythm. The discovery could provide new information about potential treatments for conditions such as heart diseases and arrhythmias.

Empatzis marveled at the complexity of this intrinsic neural mechanism and said better understanding it could lead to novel therapeutic targets.

The researchers’ goal is to figure out how this “heart brain” communicates with the central brain under various circumstances, including exercise and stress.

The collaborative study was supported by multiple foundations and highlights the need for further investigation into how disruptions in this neuronal network may contribute to various cardiovascular disorders.

As researchers continue to decode this complex system, they hope to open new avenues for treating heart disease and enhancing heart health.