Biological complexity: bacterial memory (Introduction)

by David Turell , Tuesday, April 28, 2020, 01:21 (1671 days ago) @ David Turell

Using light the membrane potential is changed in bacteria and they remember the stimulation some hours later:

https://www.cell.com/cell-systems/fulltext/S2405-4712(20)30116-2

Summary:

"Cellular membrane potential plays a key role in the formation and retrieval of memories in the metazoan brain, but it remains unclear whether such memory can also be encoded in simpler organisms like bacteria. Here, we show that single-cell-level memory patterns can be imprinted in bacterial biofilms by light-induced changes in the membrane potential. We demonstrate that transient optical perturbations generate a persistent and robust potassium-channel-mediated change in the membrane potential of bacteria within the biofilm. The light-exposed cells respond in an anti-phase manner, relative to unexposed cells, to both natural and induced oscillations in extracellular ion concentrations. This anti-phase response, which persists for hours following the transient optical stimulus, enables a direct single-cell resolution visualization of spatial memory patterns within the biofilm. The ability to encode robust and persistent membrane-potential-based memory patterns could enable computations within prokaryotic communities and suggests a parallel between neurons and bacteria. "

A science report about this finding:

https://cosmosmagazine.com/biology/bacteria-with-robust-memories?utm_source=Cosmos+-+Ma...

"Previous research by Süel and others has shown that bacteria use ion channels to communicate and suggested they might also have the ability to store information about their past states.

"In the new study, the researchers were able to encode complex memory patterns in bacterial biofilms with light-induced changes in the cell membrane potential of Bacillus subtilis bacteria.

"The optical imprints, they found, lasted for hours after the initial stimulus, leading to a direct, controllable single-cell resolution depiction of memory.

"'When we perturbed these bacteria with light they remembered and responded differently from that point on," says Süel. "So for the first time we can directly visualise which cells have the memory. That's something we can't visualise in the human brain.'"

Comment: What is shown is ion channel perturbations which last for some period of time. It is not magical bacterial mentation, but a demonstration of how light affects bacterial membranes.