After illumination with blue light the cation channels open and the bacterial membrane potential changes. This effect is robust and lasts for hours, even if the charge of other bacteria in the biofilm or the concentration of ions in the environment changes periodically. Bacterial memory resembles the properties of neurons so that it can be used for computations in living systems. Article published in the journal Cell Systems.
In several studies (1, 2, 3), scientists have shown that in bacteria, as in animal neurons generated action potentials — jump of the membrane charge. Interestingly, if in the cell the action potential occurred once, it is likely that it will happen again. This property is similar to the mechanism of sensitization in neurons is the simplest example of cellular memory. Perhaps some bacteria and whole bacterial communities in the biofilms can not only send each other signals about events, but also to keep the memory of them.
Scientists from the University of California in San Diego under the leadership of Gurala Suela (Gürol Süel) illuminated biofilm Bacillus subtilis (Bacillus subtilis) blue light, to cause the flow of ions through cation channels. Polarization membrane was assessed by fluorescence of fluorescent thioflavin T, a marker of membrane potential.