The heart has a “brain” of its own. And now, scientists have drawn a detailed map of this little brain, called the intracardiac nervous system, in rat hearts.
The heart’s boss is the brain, but nerve cells in the heart also have a say, These neurons are beleived to play a crucial role in health of the heart, helping to improve the heart rhythms and perhaps also protecting people against certain types of heart disease. But so far, this local control system hasn’t been mapped in great detail.
To make their map, James Schwaber, systems biologist at Thomas Jefferson University in Philadelphia and colleagues imaged male and female hearts of rat with a technique known as knife-edge scanning microscopy, creating detailed photos of the heart anatomy. The images are then be built into a 3-D model of the heart. The scientists also plucked out individual neurons and measured the amount of gene activity within each cell.
The measurements helped to arrange the heart’s neurons into separate groups. Most of the neuron clusters dot the top of the heart, where blood vessels come in and out. Some of these clusters spread down the back of the heart, and were particularly abundant on the left side. With this new view of the individual clusters, scientists can begin to study whether these groups have individual jobs.
The comprehensive, 3-D map of the heart’s little brain could ultimately lead to targeted therapies that could treat or prevent heart diseases, the authors wrote online on May 26 in iScience.