Mucus form could easily be one of the strangest life forms on our planet. They are not plants, animals or fungi, but different species of complex unicellular amoebas of the protist kingdom. Sometimes they form colonies that are able to grow, move, and even show a strange kind of intelligence.
Even without a nervous system, they can get to know the substances they encounter, retain this knowledge and even pass it on to other mucus forms. Now, a team of scientists at the French National Center for Scientific Research (CNRS) has discovered how mucus fungi actually absorb the substance into their veins.
Researchers from the CNRS Center for Animal Cognition Research led their experiments a A fascinating little fellow named Physarum polycephalum a single celled patch with multiple nuclei and a popular candidate for the study of slime form intelligence. (Here you can see how to navigate through a maze Cool!)
The team had a hunch. They had previously observed that P. polycephalum provided information on substances with other mucus globules when they mutually extended and fused their venous networks.
This implied that information about the veins was transmitted.
A similar experimental set-up was used for this next research step. Slime molds were placed near food, separated by a substance that they would have to crawl over ̵
Salt is not detrimental to slime molds, but they do not appear to be particularly hot, as they have to crawl across the water compared to a salt-free path.
As already noted, when mucus gushes over salt, they will seem to learn that it can not harm them, and they are less reluctant to go over it. This is the information that they then pass on to their colleagues.
The experiment consisted of several parts. In the first part, the team took 20 blobs and cut them in half, with the halves split into two training regimes. In the experimental group, the blobs received a nutritious oatmeal that had been mixed with salt for six days. The control group received a salt-free oat gel.
After six days, the team took measurements of salinity in the blobs. As expected, the salt group had ten times more salt than the control group.
In the second experiment, other blobs had to cross an agar bridge to reach for food. The bridge of the experimental group was salty, while the control group had a clear path.
After six days of training on these bridges, a salt bridge was presented to both groups. The experimental group crossed the bridge faster than the control group, who showed that they were used to the salt and knew it would not hurt them.
Finally, the team took 20 blob samples and injected half with water and half with saline solution. After only two hours, the salt sprayed stains behaved like those with a six-day salt-training program.
The team also investigated how long it takes for salt slime to go away Once their diet has switched back to non-adulterated oatmeal, it turns out that the blobs would excrete the salt in about two days.
There was something else interesting as well. Slime molds can become dormant if the ambient conditions are not ideal. Although active slime molds excreted the salt after two days, lumps that caused the team to rest kept it available for a full month.
"We have presented the first signs of long-term habituation in non-neural organisms and the first one looks at the underlying mechanism," the researchers write in their article.
"We are convinced that habituation is only one example of cognitive abilities that most living organisms could share, as Godfrey-Smith would say:" There are many ways to process information and control behavior A central nervous system is one possibility, but not the only one.
The research was published in Philosophical Transactions of the Royal Society B: Biological Sciences [19459005