New cell discovered in heart: mystery about its function

It looks like one of those in the central nervous system, but it's not clear what it's doing in the heart: we have no idea what role the newly discovered cell in the heart plays

In a sense, the human body still remains a mystery. There are still many things to discover and many elements whose workings are not understood. And the human body is, inevitably, one of the subjects on which scientific research focuses the most. And it's thanks to scientific research that we now know that there are cells in the heart that we've never seen before - and whose purpose we don't know.

What we know about this new cell

The study, published in the scientific journal PLOS BIOLOGY, talks about a cell similar to the glial cells that make up the nervous system. In particular, they are cells whose purpose is to nourish neurons, isolate nerve tissue and protect them from foreign bodies in the vessel of wounds. Only recently have we discovered that they transmit electrical signals, although scientists are still not sure how. They are usually found in the brain and spinal cord.

The new cell in our heart looks like a glial cell, but it's not exactly the same. It forms a kind of network around the heart. It looks specifically like an astrocyte, a star-shaped glial cell that plays an important role in building and maintaining neural networks in the spine and especially in the brain, which is full of astrocytes. But until now, they were thought to "live" only there.

There are many things that elude scientists about glial cells in general and astrocytes in particular, but one question above all has left them in doubt for years: why are they found only in the brain and spinal cord? Why not in the peripheral nervous system? So that's where scientists set out to look for glial cells.

First they looked in zebrafish, which are becoming the research world's new favorite lab rats. And they found cells that looked like astrocytes in the heart of this fish. The same cells were found in the hearts of mice and then humans: this isn't the first discovery that, starting with an animal's nervous system, could have important consequences for humans as well.

Why this new cell might be important

Formed before birth by the same group of cells that later end up "building" our faces and smooth muscles, these cells expand through the heart from its outflow tracts.

Downflow tracts are elements of the human heart that are defective in 30 percent of congenital heart disease cases, and in studying these cases, scientist Nina Kikel-Coury noticed an increase in heart rate when the flow of glial cells was interrupted. In addition, when these cells are deprived of a particular gene, the heartbeat becomes irregular.

According to Cody Smith, co-author of the study, this new cell could be the key to understanding heart disease and perhaps, at some point in the future, approaching it in a new way.

The newly acquired knowledge could bring one more piece to the heart disease puzzle, because it could explain how glial cells regulate the heart. Technology could help with that, too. But we still don't know enough to advance hypotheses.