A new study from the Institute of Biomaterials & Biomedical Engineering (IBBME) is challenging some of science’s fundamental understandings of cellular behaviour.

The foundational study, published in this month’s Proceedings of the National Academy of Sciences (PNAS), suggests that unlike what was previously understood, cells do not communicate movements by being joined, but instead move along pathways determined by physical space and ‘crowd’ flow.

“Since the 30s we’ve known that cells will follow features on their substrate. If you scratch a slide, cells with move along the scratch,” said Camila Londono (IBBME), first author of the study and PhD candidate.

Playing with this theory, the researchers had a special plate created that had striations or grooves on the surface of one side of the well, and remained flat on the other side. Cells were treated so that they would not be able to connect with one another, and then were formed into a sheet on the surface of the dual-topography wells.

In keeping with previous knowledge, the researchers found that cells moved along the grooves in groups. But what surprised the team were the cells on the flat surface in the same well.

“We found that a small fringe of cells moved as if they were on a line, as well,” states Londono.

[youtube https://www.youtube.com/watch?v=QWVW11Gq1ig]

“The best way to describe it is to say that the cells move like a school of fish,” explains Assistant Professor Alison McGuigan (ChemE/IBBME), corresponding author of the study.

The results of the study, Londono argues, point to something about cellular communication that was previously unknown.

“Researchers have always thought that signals are transferred to cells through connections to one another. But even when we prevented those connections from forming we didn’t see any difference in the signal propagation,” she said, citing that the results suggest that the cells move where they have space to move – a purely physical communication.

While the results of the study are “really new and unexpected,” according to Londono, “it’s only recently that we’ve been able to do data collection on group cell migration” due to the sheer amount of data to be collected, and the need for specific tools. In fact, the researchers collaborated with Professor Stewart Aitchison (ECE) to make the special well plate for the group.