A separate brain of the heart is found. The scientists drew a detailed 3D map of this little brain known to be the intracardiac nervous system (INC), in rat hearts.
The main part of the heart is the brain with a poorly understood nervous system. This INC works as a backup for the main brain. This tiny brain helps in tuning the external autonomic signals and keeping the heart pumping smoothly. The main function of this little brain is to protect us from diseases and maintain our good health, but scientists lack to understand its working.
Co-senior author, James Schwaber says, “The ICN represents a big void in our understanding that falls between neurology and cardiology. Our goal was to bridge that gap by providing an anatomical framework of the ICN and a foundation to understand its role in heart health.”
Intracardiac Nervous System consists of neurons spread across different parts of the heart, controlling different cardiac functions.
Co-author senior, Raj Vadigepalli, Professor of Pathology, Cell Biology & Anatomy, says, ” The only other organ for which such a detailed high-resolution 3D map exists is the brain. In effect what we have created is the first comprehensive roadmap of the heart’s nervous system that can be referenced by other researchers for a range of questions about the function, physiology, and connectivity of different neurons in the ICN.
How Did They Create A 3D Model?
Scientists used two parallel approaches to create this 3D model.
1. Knife-Edge Scanning Microscopy
The team used this approach to create 750,000 pictures and then assembled these into a single 3D atlas.
2. Laser Capture Microdissection
Using the second approach, the other team mapped individual neurons and sampled their gene expression. Those were then placed with the map obtained from the first approach.
The co-author, Sirisha Achanta, says, “Because this hasn’t been done before, we were trouble-shooting the protocol as we went along.”
The obtained 3D map indicated that ICN neurons are located in clusters at the head of the heart where the arteries and veins are attached. However, their distribution across other places close to the sinoatrial node is also possible. The co-author, Dr Jonathan Gorky, says, “We know the sinoatrial atrial node is important in creating the heart rate or pace.” He added, “Seeing the clustering of neurons around it was something we had always suspected but had never known for sure.”
The scientists tend to obtain the explanation for the different heart diseases in men and women.
The team decides to map the pig’s heart next as it is closer in anatomy to human.
“Our protocol uses everyday lab materials and techniques,” said Achanta. “It is highly reproducible and is available now for other organ systems to map not just neurons, but other micro-structures.”