Cells Can Solve Complex Mazes by Sniffing Around the Corners, Team Shows
From the perspective of a single cell, the human body is a vast ocean. There are countless ways you can take through capillaries and a plethora of tissue to go through that contain and secrete and manifolds of chemical compounds that swim around.
All this everchanging biological soup has stuff traveling around at bullet speed with each pump of the heart. Yet, in general, cells are able to go just where they need or where they're needed. This raises the question: How?
It all boils down to a phenomenon known as chemotaxis. Simply put, it's the ability to navigate through a medium by tracing the presence or absence of a chemical compound. White blood cells sniff out the infections, sperm cells the eggs, and so forth.
The researchers wanted to test the power of chemotaxis employed by the cell that traveled furthest. They created a miniature version of the Hampton Court Palace hedge maze. The results were astounding, the amoebas darted to the exits with astounding accuracy, "seeing around corners" and avoiding dead-ends before even hitting them, according to author Robert Insall.
Insall, a professor of mathematical and computational cell biology at the University of Glasgow in Scotland, said, "The cells aren't waiting for someone to tell them what to do," to Live Science.
"By breaking down the chemicals in front of them, they know which branch of the maze leads to a dead-end and which leads [to the exit]. It's absolutely unbelievable."
In this study, the team focused on a specific form of chemotaxis known as "self-generated chemotaxis". The logic is simple, cells want to be in the presence of an attractant, they utilized an acidic solution called adenosine monophosphate for this.
Insall likens the cells to a herd of cows, it's like cows grazing around, he says "The cows have eaten all of the grass where they are, and they want to get into the surrounding field where the grass is still growing."
So the cells break down the attracting solution around them, through diffusion, more of the solution moves towards them. When they face a quick depletion, they simply don't go that way and seek for a juicier path.
They first used computer models to model the phenomenon and wanted to move on to the real deal. So they etched over a hundred silicon mazes. They covered many different difficulties but Insall noted that an exact replica of Scotland Traquair House maze didn't hold up well, as all the cells perished before solving the puzzle.
It took between 30 minutes to 2 hours for amoebas to solve the mazes.
Although the study focused on amoebas, the researchers suggest that the same phenomenon holds with the human cells, whether it's a cancerous glioblastoma trying to reach the white matter in the brain or white blood cells trying to locate an infection.