FREQUENCY COUPLING MODEL FOR DYNAMICS OF RESPONSES TO STIMULI IN PLASMODIUM OF PHYSARUM-POLYCEPHALUM

Gathering or escaping behavior in the plasmodium of Physarum polycepha lum is considered to relate to an entrainment of the coupled nonlinear oscillators. The behavior has been explained to be caused by the form ation of phase gradient between those oscillators, which results from the local frequency modulation at the stimulated site. However, it has not yet been elucidated how the formation process relates to the migr ation of the plasmodium. In this paper, we have introduced a model wit h frequency coupling besides the phase coupling in the system of coupl ed oscillators. By the simulation, we have shown that not only the pha se gradient but also the concentration gradient of substances such as Ca2+ and ATP are self-organized and their reverse by the stimulus resu lts in the migration of plasmodium.