Why are these microbes playing 'Pac-Man'?

A team of Norwegian researchers created a 3D maze based on the classic arcade game to study how some of Earth's tiniest creatures prey on others.

For a team of Norwegian researchers, a tiny labyrinth modeled on the 1980s arcade game “Pac-Man” provides the ideal environment to study a real-life cat and mouse game involving microorganisms.

In a video produced by the researchers at the University College of Southeast Norway, single-celled euglena and ciliates take on the role of Pac-Man as they are chased through a liquid-filled, 3D maze by multi-celled rotifers, much like the original game’s hungry ghosts.

The researchers say recreating a tiny version of the game – less than a millimeter in diameter – offers both scientific benefits and the additional bonus of being able to better communicate their research to the public.

Created with the help of filmmaker Adam Bartley, it’s also “tremendous fun,” they note in a blog post (translation via Google Translate).

The maze’s neon blue top-light and lens flare effects make for an attractive visual package, but scientists who create these kinds of publicity-friendly contrivances run the risk of alienating their funders, particularly in the United States, where scientists frequently face skepticism from Congress when it comes to explaining the utility of their research. 

One example, is an infamous study that involved examining how marine organisms fight infections – partly by putting shrimp on a treadmill.

A video clip of the experiment was widely shared and excoriated by Republicans in Congress, who used it as an impetus to investigate what they argued was wasteful spending in projects backed by the National Science Foundation.

While Forbes claimed the experiment cost $3 million, David Scholnick, a marine biologist who conducted the experiment, noted that the treadmill was made of spare parts and cost only $47, which he paid out of his own pocket, he wrote in a 2014 column in The Chronicle of Higher Education.

“It is disingenuous for the Republican-controlled House Committee on Science, Space and Technology to promote the idea that scientists are wasting millions of taxpayer dollars to run shrimp on treadmills based on a 30-second video clip,” he wrote.

“The health of the organisms that inhabit the largest ecosystem on the planet and the potential bacterial contamination of the food we eat are serious and important questions. I, like many of my colleagues, are deeply concerned by the minimization and politicization of our work,” Dr. Scholnick added.

For the researchers in Norway, the Pac-Man-like maze also helps solve another problem that researchers face in studying microorganisms in Petri dishes, says Erik Andrew Johannessen of the school’s department of micro and nanosystem technology, in their blog post. 

In that environment, the tiny creatures have little room beyond the surface of the dish, which can create a problem because of the limited depth of field in light microscopy, Motherboard reports.

Creating a “micromaze,” by contrast, allows the researchers to better study the organisms in an environment that mimics the complex series of canals found in their nature habitats, such as peat or moss.

They hope to further expand the project to digitally track the tiny creatures to determine whether there is further logic in their seemingly random movements, according to the blog post.