Design of transportation network by an amoeba-like organism

Toshiyuki Nakagaki & Ryo Kobayashi

Research Institute for Electronic Science
Hokkaido University
Sapporo 060-0812, Japan

We report here evidence that an effective transportation network is designed by an amoeba-like organism of true slime mold Physarum polycephalum, which has network of tubes to transport chemical materials all through the organism. When many food-sources were distributed on an agar plate where the organism crawled, the organism found them and changed the network shape to connect the food-sources through only a few tube. Geometrical shape of the network is drastically variable depending on a set of locations of food-source. Statistical observation shows that the network geometry meets multiple requirements for effective network; short total length of tubes, close connection (small number of transit food-sites between any two food-sites) and fault-tolerance against an accidental disconnection of tubes. Local self-sustained cellular rhythms interact each other in the organism and pattern formation of the cellular rhythm underlie in mechanism of development of tube-network. Along this line, a mathematical model for self-organization of transport network is proposed and discussed.


1. T. Nakagaki et al., Biophys. Chem. 84, 195 (2000).
2. T. Nakagaki et al., Nature 407, 470 (2000).
3. T. Nakagaki et al., Biophys. Chem. 92, 47 (2001).
4. T. Nakagak., Res. Microbiol. 152, 767 (2001).