Scientists have discovered a new type of cell in the heart. The cells, now called nexus glia, appear to help regulate heart rate and rhythm, and the team says they could unlock new knowledge about certain heart defects and diseases.
Glial cells are found in the brain & nervous system, where they support and structure for neurons. They can also be found in some major organs, where the peripheral nervous system extends to them, but glial cells have never been found in the heart until now. So, for the new study, researchers at the University of Notre Dame set-out to search for them.
And indeed, when examining zebrafish hearts, they found cells that look like astrocytes, a type of glial cell found in the brain. Follow-up investigations have also uncovered new cells in mouse and human hearts. The new cells, which the researchers called nexus glia, are found in the exit pathway, which is part of the structure through which blood flows when it leaves the heart.
Further investigation suggests that the glia link plays a key role in regulating heart rate and rhythm. When the team removed the cells from the animals’ hearts, their heart rate increased. In animals that were designed to lack a gene that drives glial cell development, their heartbeat became irregular.
The team says the discovery could have implications for certain types of heart defects and diseases. Some of these conditions are associated with irregular or rapid heartbeats and, oddly enough, many congenital heart defects are found in the ejection tract, where the glial link was found. Scientists say it’s too early to tell, but the discovery could open new avenues for future research.
“We don’t fully understand the function of these cells, but the concept that if you remove them your heart rate increases could link them to some cases of the disease,” says Cody Smith, lead researcher on the study. “I think these glial cells could play an important role in regulating the heart. It’s a discovery that we now have 100 questions we didn’t even know existed, so we’re following them to explore this path that never has. been studied before.
The research was published in the journal PLOS Biology.