For one cell is the body is a giant maze of tissues, chemicals and capillaries, filled with trillions of other cells, all crowded as commons at the busiest train station in the world. Somehow, most cells in the middle of all this hubbub still managed to reach their destinations.
How do they do it? Many cells have a trick in their sleeves, known as chemotaxis – essentially the ability to navigate by observing the presence or absence of chemical noises in the environment. Seed cells use chemotaxis to find eggs, white blood cells use it to rally around infection sites and cancers cells use it to metastasize through vulnerable tissues.
So, can an amoeba use chemotaxis to solve the world’s most infamous hedge maze? That’s exactly what happened in a new study published today (August 27) in the journal Science.
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To test the potency of a specific form of gemotaxis used by the farthest traveling cells, researchers made miniature versions of the hedge maze at Hampton Court Palace (once the residence of King Henry VIII and its progeny) plus dozens more microscopic labyrinths of varying complexity. It is noteworthy that when amoebas were released into these mains, they shot to the exits with incredible unbelief, using chemotaxis to effectively “look around corners” and prevent dead-ends before they even reached them, said author Robert Insall.
“The cells are not waiting for someone to tell them what to do,” said Insall, a professor of mathematics and computational cell biology at the University of Glasgow in Scotland, WordsSideKick.com. “By breaking down the chemicals for them, they know which branch of the maze leads to a dead-end and which leads [to the exit]. It is absolutely unbelievable. “
Cells in a maze
In their new study, the researchers focused on a specific form of cell navigation called “self-generated” chemotaxis. It relies on a simple philosophy: cells want to move from areas of a lower concentration of sound medium (in this case an acidic solution called adenosine monophosphate) to areas with a higher concentration.
“It’s like the old saying, ‘the grass is always greener on the other side of the fence,'” Insall said. “The cows have eaten all the grass where they are, and they want to get into the surrounding field where the grass is still growing.”
But sometimes there are multiple “fields” to choose from, illustrated in this study by the multiple branching paths of a maze. To determine which branch has attracted the higher concentration, cells break down the molecules in front of them, causing sound medium to spread from the nearby areas to them. As the cells move forward, the attraction to them increases more and more; eventually, short, dead-end branches of the maze are completely stripped of attractiveness, even before the cells reach the exit to a dead end. When confronted with a short, impoverished branch and a long, attractive-filled branch, the cells will never take the dead-end route, Insall said.
“They can really look around corners,” Insall said.
The researchers illustrated this phenomenon with computer models at the beginning of their study, but also wanted to see it in action. That is, they created more than 100 microscopic targets by etching grooves on a silicon chip, each path between 10 and 40 microns wide. (For comparison, the thinnest human hairs measure about 20 microns wide).
Mazes range from easy (but a few branching paths before the exit) to difficult (with long dead-end paths, such as the Hampton Court hedge maze replica) to impossible (according to Insall, a replica of Scotland’s Traquair House Maze had to be scrapped because all the amoebas remained dead before solving the puzzle).
The researchers smeared these small labyrinths in rubber, and then flooded them with a liquid sounding agent that was introduced from the maze exit. At the beginning of each maze, ground bogs called out Dictyostelium discoideum set up and began to swim forward, breaking down the fluid molecules in front of them. The longest targets lasted about 2 hours for the bad cells to resolve, Insall said, while the shorter ones lasted only 30 minutes.
The real life cells performed exactly as the models of the team predicted; when confronted with the choice between a short dead path and a long path leading to the exit, the cells always chose the long path. In harder labyrinths, which contained dead-end paths that were just as long as the right path, cells chose correctly about 50% of the time. In both cases, cells that first entered the maze were most likely to reach the exit; cells that struggled to find that every path, even the right one, had already been pulled out by their competitors was attractive, leaving the fighters with no information on where to go.
“The amount of information cells can read by breaking down chemicals is much more refined than anyone thought,” Insall said. “That makes us think that most biological problems, where cells have to find their way from one place to another, almost certainly use a mechanism like this.”
Even though the study focused on amoebas, the researchers believe the results should be true for any number of human body cells – whether it’s blood cells that shoot through tissues to reach an infection, or cancerous glioblastoma cells that swim through channels of the brain swim. The type of attraction is likely to be different in each situation (and, in many cases, is still unknown to scientists), but for cells navigating through the tortuous labyrinth of our bodies, figuring out where the greener grass is is best. be way to go.
Originally published on Live Science.
