A. Takamatsu et al., Control of interaction strength in a network of the true slime mold by a microfabricated structure, BIOSYSTEMS, 55(1-3), 2000, pp. 33-38
The plasmodium of the true slime mold, Physarum polycephalum, which shows v
arious nonlinear oscillatory phenomena, for example, in its thickness, prot
oplasmic streaming and concentration of intracellular chemicals, can be reg
arded as a collective of nonlinear oscillators. The plasmodial oscillators
are interconnected by microscale tubes whose dimensions can be closely rela
ted to the strength of interaction between the oscillators. Investigation o
f the collective behavior of the oscillators under the conditions in which
the interaction strength can be systematically controlled gives significant
information on the characteristics of the system. In this study, we propos
ed a living model system of a coupled oscillator system in the Physarum pla
smodium. We patterned the geometry and dimensions of the microscale tube st
ructure in the plasmodium by a microfabricated structure (microstructure).
As the first step, we constructed a two-oscillator system for the plasmodiu
m that has two wells (oscillator part) and a channel (coupling part). We in
vestigated the oscillation behavior by monitoring the thickness oscillation
of the plasmodium in the microstructure with various channel widths. It wa
s found that the oscillation behavior of two oscillators dynamically change
d depending on the channel width. Based on the results of measurements of t
he tube dimensions and the velocity of the protoplasmic streaming in the tu
be, we discuss how the channel width relates to the interaction strength of
the coupled oscillator system. (C) 2000 Elsevier Science Ireland Ltd. All
rights reserved.