Diversity in the chemotactic behavior of physarum plasmodium induced by bi-modal stimuli

The plasmodium of the true slime mold Physarum polycephalum is a unicellular, multinuclear giant amoeba that is attracting much attention in the field of bio-computing as a living computing substrate. To observe how the plasmodium of Physarum polycephalum responds to a contradictory situation, in which there is no single optimal solution, we applied bi-modal stimuli, consisting of a mixture of an attractant and a repellent, to plasmodia. The plasmodia showed diverse responses that could not be explained by a simple model of the stimulus-response system. We constructed a simulation model of the behavior that replicated the behavioral diversity with a simple combination of molecular apparatuses. In summary, we demonstrated the diversity of the behaviors of the plasmodium and how these behaviors may arise.