Heart Birth Filmed in 3D in a Mouse Embryo

For the first time, the birth of the heart has been filmed in 3D in a mouse embryo , that is, the exact moment in which the cells begin to specialize and organize themselves to give shape to the first outline of the organ: this is the important result obtained by a group of researchers led by University College London, published in the Embo Journal of the European Molecular Biology Organization.

The study could change our understanding of congenital heart defects , which affect nearly one in 100 newborns , and how to correct them , opening up the possibility of intervening at much earlier stages . But the findings could also accelerate progress in growing heart tissue in the lab , for use in regenerative medicine . "This is the first time we've been able to observe heart cells so closely and for such a long time during mammalian development," said Kenzo Ivanovitch, who coordinated the study. "We initially had to grow the embryos in the lab for long periods, from a few hours to a few days, and what we found was completely unexpected." To achieve this, the researchers used a particularly advanced technique called ' light sheet microscopy ': in practice, the laser beam used to illuminate the sample is concentrated until it forms a sheet of light that illuminates only a very thin layer of the sample at a time. In this way, very detailed 3D images are obtained without causing any damage to living tissue .

Using this technique, the study's authors were able to follow individual cells over the course of two days , taking images every two minutes : from a critical stage of development known as gastrulation , the process by which cells begin to specialize and organize themselves, which in humans occurs during the second week of pregnancy, up until the moment when the primitive heart takes shape.

The images show how the cells that give rise to the heart emerge very quickly and behave in a highly organized way : they do not move randomly, but follow very precise paths, as if they already knew the role they will have to play. "This radically changes our understanding of cardiac development," says Ivanovitch, "demonstrating that what seems like chaotic cell migration is actually regulated by hidden patterns that ensure the correct formation of the heart ."