Researchers at the Max Planck Institute for Dynamics and Self-Organization in Germany have determined how the Physarum polycephalum slime mold retains memories despite the absence of a nervous system. It turned out that he imprints information about the location of food in the structure of his own body. An article revealing the secret of intelligent living goo was published in the journal Proceedings of the National Academy of Sciences.
It is known that Fusarium is able to find the optimal solution to some complex mathematical problems, including the traveling salesman problem (TSP). TSP is to find the most profitable (shortest) route passing through several cities, while each city can be visited only once and you need to return to the starting point. Previous experiments have shown that a slime mold is able to approximately solve a problem in linear time, but how exactly it manages to do this remains a mystery.
Physarum polycephalum is a giant cell that can form branching tubular structures that help find food around the body. The tubular network is capable of rapidly changing, reorganizing itself in such a way as to most efficiently extract nutrients from the environment. At the same time, the slime mold does not have a single coordinating center, and “memories” of the location of food are encrypted in the very architecture of the body (mycelium) of the organism. This stored information is then used to make future decisions.
Scientists have observed changes in the structure of the slime mold and combined the findings with theoretical models. Food contact releases a chemical that spreads throughout the body and causes it to reorient the mycelium towards food. Although the structure of the cell itself, as a whole, remains dynamic, the researchers found that it retains a “fingerprint” formed by the specific arrangement of thin and thick tubes. In this case, the thick tubes facilitate transport for the signaling substance. Thus, the slime mold stores information about past contacts with food sources, which affects future behavior.
The Physarum polycephalum study could inspire the development of intelligent materials and soft-bodied robots capable of navigating challenging obstacles, scientists said.
