A rare view inside a beating heart cell
A team of researchers led by Benjamin Prosser of the University of Pennsylvania Perelman School of Medicine, who were funded by the National Institutes of Health, recently captured video showing that a part of a heart muscle cell called the microtubules act as molecular shock absorbers.
Microtubules are dynamic filaments that play a key role in the structural support and movement of cells along with transporting their intracellular cargo, according to the NIH. Previously, they were thought to be "very rigid."
As for why this matters for your everyday person, the director of the NIH, Dr. Francis Collins, writes:
"As described for the first time recently in the journal Science, the microtubules buckle under the force of each contraction of the muscle cell before springing back to their original length and form. The team also details a biochemical process that allows a cell to fine-tune the level of resistance that the microtubules provide. The findings have important implications for understanding not only the mechanics of a healthy beating heart, but how the abnormal stiffening of heart cells might play a role in various forms of cardiac disease."
In the past, the role of microtubules in the contraction of heart muscles was mostly unexplored - partially because it's difficult to capture all the moving parts of a living heart cell. After all, as the NIH's Dr. Collins notes, a complete contraction of the heart muscle takes place in about 0.10 seconds.
In any case, check out a GIF of the beating heart cell below: