Amazing similarities between bacterial memory and neurons in the human brain

Tariq Kabil

Biologists have discovered that bacterial biofilms contain a "memory" that works in a manner similar to the way human neurons operate, which opens the way for the results of this study to be used in the development of biological computing science and artificial biology.

Professor Gurol Sowell and his colleagues at the University of California, San Diego, found that light-stimulating bacteria cells remembered exposure to light after hours of first stimulation.

The results, published in the journal "Cell Systems" on April 27, show surprising similarities between primary single-celled organisms and complex neurons that treat memory in the human brain.

Bacteria remember
the delicate bacterial biofilm (biofilm) is a complex accumulation of single-celled microorganisms, characterized by the secretion of extracellular tissue, and cells adhering closely to each other, often these cells adhere to a solid surface.

The team used simple bacteria called "Bacillus subtilis", a type of "gram-positive bacteria" present in the soil, and exhibited a five-second flash of blue laser light.

Researchers found that this light causes a change in the membrane, where ions flow continuously from the cell and then return to it again, and this effect remained for several hours after exposure to light.

"Our work shows for the first time that simple bacteria can encode memory at the cellular membrane level, which is similar to the process of memory of neurons in the brain," Professor Soil, a University of California molecular biologist, told the Science Alert website.

"We were surprised when we found that the mechanism by which memory is formed is similar between bacteria and neurons, because these are evolutionary systems that are very far from each other."

Ancient roots
After recent discoveries from Sewell's laboratory confirmed that bacteria use ion channels to communicate with each other, the new study suggests that bacteria may also have the ability to store information about their past states.

And although it appears to be a form of memory formation, it is certainly not the same as what happens in our brains. When neurons “release” neurons in our brains, ions flow and inform the next neuron that it has received a message.

The flow of ions results in a difference in the electrical charge between inside and outside the cell, and this change in the potential of the cellular membrane of neurons is known to be involved in the process of memory formation.

The great importance of this change is the transfer of information between neurons or the transfer of information between the tissues of the body and the brain. Now, it looks like something similar can happen in the biological membranes of bacteria, but we don't yet know why it occurs, or whether the bacteria actually use it in their normal environments.

"We do not yet know why the bacteria have this property ... It is clear that we need to study more deeply what it means for the bacteria to be exposed to light and create memories," Sowell explains.

"Even a few years ago, people did not believe that bacterial and nerve cells are similar to anything because they are different cells ... and this discovery in bacteria provides clues and an opportunity to understand some of the main features of the brain in a simpler system."

Collective memory
This is not the first time that researchers have found bacteria that "remember" things. A few years ago, another team of researchers found that bacteria have a collective memory that increased their tolerance to stress when exposed to salt.

Sowell's team hopes to be able to use its recent findings to develop computing systems and synthetic biology, but it appears that this may need more time.