Taha Laroussi, Mojtaba Jarrahi, Gabriel Amselem
Phototaxis, the directed motion in response to a light stimulus, is crucial for motile microorganisms that rely on photosynthesis, such as the unicellular microalga Chlamydomonas reinhardtii . It is well known that microalgae adapt to ambient light stimuli. On time scales of several dozen minutes, when stimulated long enough, the response of the microalga evolves as if the light intensity were decreasing [A. Mayer, Chlamydomonas: Adaptation phenomena in phototaxis, Nature , 1968, 217 (5131), 875-876]. Here, we show experimentally that microalgae also have a short-term memory, on the time scale of a couple of minutes, which is the opposite of adaptation...
April 30, 2024: Soft Matter