Simultaneous coupling of phototaxis and electrotaxis in Volvox algae.
In nature, living creatures are affected by several stimuli simultaneously. The response of living creatures to stimuli is called taxis. In order to reveal the principles of taxis behavior in response to complex stimuli, we simultaneously applied photostimulation and electric stimulation perpendicularly to a Volvox algae solution. The probability distribution of the swimming direction showed that a large population of swimming cells moved in a direction that was the result of the composition of phototaxis and electrotaxis. More surprisingly, we uncovered the coupling of signs of taxis, i.e., coupling of phototaxis and electrotaxis induced positive electrotaxis, which did not emerge in the single stimulation experiments. We qualitatively explained the coupling of taxis based on the polarization of the swimming cells induced by the simultaneous photo- and electric stimulation.
Brain Embodiment Laboratory, School of Systems Engineering, University of Reading, PO Box 225, Whiteknights, Reading RG6 6AY, United Kingdom.
Yoshikatsu
Y
Hayashi
Department of Information Science, College of Liberal Arts, Tohoku Gakuin University, 2-1-1 Tenjinzawa, Izumi-ku, Sendai, Miyagi 981-3193, Japan.
Ken
K
Sugawara
D002465:Cell Movement / Q000502:physiology*; D016764:Cell Polarity / Q000502:physiology / Q000528:radiation effects; D003198:Computer Simulation; D004558:Electric Stimulation / Q000379:methods*; D040542:Mechanotransduction, Cellular / Q000502:physiology*; D008954:Models, Biological; D010775:Photic Stimulation / Q000379:methods*; D044446:Volvox / Q000502:physiology*