The brain in advanced organisms such as animals sends nerve signals that are responsible for jumping, running and movement in general, but this is not the case in micro-proto-organisms that do not have brains at all to move a complex movement like more advanced organisms, and instead slip or roll Or swimming in ponds.
In contrast to its common counterparts, single-celled Euplotes eurystomus have demonstrated the ability to complex locomotion with the help of precise and orderly internal programming that can be considered an internal mechanism.
This interesting ability of these organisms was monitored by the results of researcher Ben Larson at the University of California, San Francisco in the United States in a study published on December 22 in the journal Current Biology. ).
A new discovery refutes a previous hypothesis
According to an October 6 press release from the University of California, San Francisco, Larson et al. analyzed the locomotion of single-celled opalites, which use 14 synaptic cilia to make their own cilia. Legs-like and known as "Cirri", and these cilia enable them to move and move across different surfaces. What caught the researchers' interest is that this movement involves unusual locomotion with typical repetition.
Since the early twentieth century, it has been believed that there are protoplasmic links between the cilia of those organisms that control their movement, as microsurgical experiments have supported a previously hypothesized mechanism for coordinating movement in microorganisms, and this movement is attributed - according to the dominant hypothesis for a long time - to the plasma membrane, which acts as a conductor of electrical impulses , which negates the possibility of a conductive property that distinguishes the internal structures of cells such as different motor nerve fibers, but the newly observed results contradict what was previously thought.
The results show for the first time that fine networks between these cilia control their movements in a way that allows the legs to move only in certain patterns and sequences. But when these internal connections are disrupted, these organisms are unable to move and this leads to a lack of sequence, and they often resort to spinning in circles rather than walking in a single line.
Precision kinematic mechanism
This exciting discovery began with microscopic observations of opalus creatures, and at first glance Ben Larson thought that he was examining a type of animal through the lens of a microscope, a type similar to insects, but soon realized that what was wandering in front of him was in fact a type of single-celled microorganism, and what sparked interest Larson's fascination with these creatures is their amazing ability to coordinate the movement of their 14 cilia and use them as legs without a brain or even a nervous system.
To understand this extraordinary ability, Ben Larson and Wallace Marshall have studied these creatures and tried to understand in more detail how they control movement. The researchers watched video clips at a slow speed of the oblouses during walking and movement, and took about 33 images per second, and then numbered each of the cilia to facilitate tracking and analysis of their movement while walking.
The researchers described 32 gait states, which showed the presence of certain patterns that tend to follow each other, and this led Larson to believe that there is a sequential logic accompanying this movement, and this discovery raised both interest and doubt in the existence of a type of data processing that governs all of this.
Commenting on the findings, Wallace Marshall, a professor of chemistry and biophysics at the University of California, San Francisco, one of the principal investigators and study leader, said in the press release, “Oplots use these networks to facilitate complex, subtle gait, but I think when we expand research into how this happens, The thing is, we will find that there are other types of cells that adopt similar forms of internal computing to control more precise operations."
Microfiber mesh
The cilia of opallots consist of tubulin protein fibers, and like the rest of the cellular structures; These fibers act as a support structure for the cilia, so they also provide a kind of mechanical connection between them.
Computer modeling has helped in understanding how these fused cilia control the walking movement of opalus creatures, as the modeling showed that the amount of stress and strain exerted on those fibers is what governs a particular gait pattern at a particular moment, just as if it were a mechanical structure of the moving bamboo structures known as Strandbeast , designed by Dutch artist Theo Jansen to walk and interact with its environment.
It has been observed that some cilia may retain the compressive energy at certain stages of movement, and upon release from it, it prompts the cell to proceed to the next walking pattern, forming a typical sequence of walking states that made Marshall describe its mechanism of action in a primitive computer.
To further understand this mechanism, the opallots were exposed to a drug that disrupts the synchronous interactions of tubulin fibers, which disrupted the cell's gait and movement pattern. However, their gait remained regular, but they were no longer coordinated in a way that allowed effective movement, and instead began to spin in useless circles.
Hence, the researchers concluded that these single-celled organisms - which lack a brain and a nervous system - can control their movement and gait patterns through networks of protein molecules capable of exchanging signals among themselves, and work regularly as clock gear that produces a patterned movement, calculated and very accurate .
There is still a lot to understand
The researchers acknowledge that the results of the study are not sufficient to understand the mechanics of movement in these organisms and how the protein microfibrils network controls their movement in particular, but computer models as well as microscopic experiments indicate an entirely new mechanism for the cell that enables its gait and movement patterns.
"This discovery is an exciting and fascinating biological phenomenon in itself, but it also highlights more general computational processing in other types of protocells," Larson says.
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