The memory of unicellular organisms twists our understanding of intellectual life

Slime research It may not be the sexiest science, but it really produces some Wild results..Very wild, in fact, new research does more than just reconstruct our understanding Animal intelligence, Not only very Memory idea..

What’s New – The· SurveyPublished in the journal on Monday Minutes of the National Academy of Sciences, How to accurately investigate giant slime molds (Physarum polycephalum) Encoding memories Depending on the food source.

According to researchers, this study provides clues on how biological signals generate and alter memory, even in the simplest creatures.

Karen Alim He is a co-author of this study and a professor at the Technische Universität München, Germany.She tells Reverse This study takes what we already knew about these strange creatures and brings them to mind.

“There is previous research that biological signals within slime molds can store information about previous experiences,” says Alim. “But network architectures can store memory [a] A novel concept in the context of slime molds and fungi. “

How they did it — Both Alim and her team observed slime molds in a laboratory setting and generated a theoretical model to assist in the calculations.

Using images generated from observations and models, they use the newly introduced food sources of the organism’s tubes (essentially the mucous tendrils that emanate from the organism as it passes through the environment). Decided to change.

First, scientists calculated changes in the diameter or size of these tubes in response to new food sources, and what slime molds did over several hours.

They found that it took 45 minutes to reorganize the entire network of tubes so that slime molds face the food source. Around 90 minutes, the mold began to move towards the food source. And after 310 minutes, slime mold swallowed the food source almost completely.

Surprisingly, as scientists reduced the size of the mold, the organisms reorganized even more quickly. Studies show that small slime molds began to reorganize tubes within 15 minutes and began to move towards food sources within 45 minutes.

Dictyostelium is known to make decisions within 10 to 20 [minutes], “According to research. But what propelled these decisions was more vague. These new results provide some clues. As researchers explain in their studies, slime molds appear to achieve their prominent reorganization as a result of encoding food locations sourced through a network of tubes.

Delve into the details — To test this idea, scientists used simulated mold to show how a mysterious agent from a food source invaded a slime mold tube. In the simulation, researchers unleashed the softener, which caused the tube closest to the food to swell or expand.

Tubes far from the food source do not expand as much as tubes closer to food and essentially establish a hierarchy of tubes.Then a engorged tube Engrave the memory Of the nutrient source of that network.

However, this is not a one-time response.Rather, studies show that slime molds “irreparably changed” the flow pattern of their tubes-a sign. Long-term memory formation..

These findings unlock the “missing part of the puzzle” to explain how slime molds are permanently reorganized in response to nutrients.

In short: Dictyostelium encodes the memory of nutrient sources in the tube. Studies show that the longest-surviving tubes are those that “directly have memories of the nutritional stimuli that led to growth.”

“Therefore, memories stored in the hierarchy of tube diameters, especially in the location of thick tubes, are then layered on top of each other, and all new stimuli discriminate against existing thick tubes in the superposition of existing memories. Strengthen and weaken. ”

Important reason — This study suggests that creatures lacking the nervous system, that is, the following creatures, are capable of memory formation. Fungi Or slime mold.

“We believe our research will change our perception of every flow network in life, whether it’s our own vascular system or a network formed by slime molds and fungi,” Alim said. say.

In most animals, memory is usually formed as a result of synaptic plasticity. This allows the brain to establish connections through specific neuronal and synaptic networks that are strengthened over time.

Dictyostelium has no synapses or no nervous system at all. However, this study shows that it effectively mimics synaptic plasticity by encoding memory with a tube network instead.

Memory formation was previously thought to exist only in high-level organisms like us, but now researchers are beginning to understand that idea. Even the simplest life forms have memories..

What’s next- This research gives researchers more impetus for exploring slime molds in science.For example, slime molds can break down both arms (also known as “”Multi-armed “) Bandit problem, this is a related problem Complex decision making.

Dictyostelium is also very good at finding the shortest route between food sources in the maze.These molds are made by mathematicians Traveling salesman problem, Try to find the shortest route for delivery drivers between cities.

Soon, the researchers behind this study want to understand the chemistry that acts inside the tube as it changes shape in response to food.Scientists say that the chemicals that soften the tubes Adenosine triphosphate, A chemical that carries energy. Future research may delve into other properties and uses of this strange substance.

Researchers believe that their findings could have unimaginable implications for biology-inspired designs in other areas, such as: Robotics.. Much of the current research on artificial intelligence Nervous systemHowever, this study provides a new and innovative source of inspiration. AI researcher..

“There is a lot of research aimed at designing soft robots and building autonomous and intelligent systems. The mechanism for storing the information we have discovered is Physarum It will be very inspirational in this area, “says Alim.

Overview: The concept of memory is traditionally associated with organisms that have a nervous system. But even very simple organisms store information about past experiences in order to thrive in complex environments. Make good use of nutrients, avoid dangers and drive off predators. How can a simple organism encode information about the environment? Here we track how the giant unicellular slime mold Physarum polycephalum reacts to nutrient sources. It turns out that body plans, such as the network of organisms themselves, help encode the location of nutrient sources. Organisms are made up of interwoven tubes of completely different diameters. Here, we observe that these tubes expand and contract in diameter depending on the nutrient source, thereby imprinting the position of nutrients in the tube’s diameter hierarchy. Combining theoretical models with data reveals how memory is encoded. Nutrient sources locally release softeners that are transported by the cytoplasmic flow within the tubular network. Tubes rich in softeners increase in diameter at the expense of shrinkage of other tubes. Thereby, the capacity of the tube for flow-based transport is permanently upgraded towards the location of nutrients, redirecting future decisions and transitions. This indicates that nutrient positions are stored in and derived from the tube diameter hierarchy of the network. Our findings explain how network-forming organisms such as slime molds and fungi reproduce in complex environments. Here you identify the version of the flow network’s associative memory. This is very likely related to an excess of living flow networks and bio-inspired design.