title: Tactic direction determined by the interaction between oscillatory chemical waves and rheological deformation in an amoeba.
abstract: The survival of an organism can depend upon the direction in which it decides to move in response to changes in external conditions. Here we propose a physicochemical mechanism of the decision process for migration direction in the case of a giant amoebalike Physarum plasmodium. The tactical movement response could be changed by reversal of the phase wave of the rhythmic contractions that occur in any part of the plasmodium body when local stimulation is applied and the frequency of the rhythmic contractions is locally modulated in the stimulated region. The proposed model describes a physicochemical mechanism of coupling between the local modulation of frequency and the global transport of protoplasmic mass. The decision process is clarified from a rheological point of view.
authors.affiliation: Department of Life, Information and System Sciences, Graduate School of Science and Engineering, University of Toyama, Toyama 930-8555, Japan.
authors.forename: Kei-Ichi
authors.initials: K
authors.lastname: Ueda
authors.forename: Seiji
authors.initials: S
authors.lastname: Takagi
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Nakagaki
mesh_terms: D001683:Biological Clocks / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology*; D048429:Cell Size; D003198:Computer Simulation; D006244:Hardness / Q000502:physiology; D040542:Mechanotransduction, Cellular / Q000502:physiology*; D008954:Models, Biological; D010961:Plasmodium / Q000502:physiology*; D014110:Touch / Q000502:physiology*