Information propagation by spatio-temporal pattern change of Ca2+ concentration throughout Physarum polycephalum with repulsive stimulation.
The development of a spatio-temporal pattern of Ca2+ concentration (Ca2+ pattern) in the plasmodium of Physarum polycephalum during repulsive response was studied using fura-2. In the migrating cell, the gradient of the Ca2+ concentration (Ca2+ gradient) immediately showed a decrease in local concentration in the area (S-site) stimulated by 50 mM KCl. The concentration rose and then decreased in a site neighboring the S-site. This transient increase of Ca2+ concentration, the duration of which was approx. 10 minutes, was propagated to the site most distant from the S-site. There, the Ca2+ concentration gradually rose and remained at a high level. Twenty-five minutes after stimulation, a new Ca2+ gradient was established throughout the plasmodium. The migratory direction of the cell as a whole then changed. In this process, although the period of Ca2+ oscillation changed at the S-site, this change was only local to the site. During the information processing of the local repulsive stimulus, the transient Ca2+ increase propagated the local information about the stimulus to the non-stimulation sites (NS-sites), leading to the generation of a new pattern and the start of coordinated migration of the plasmodium.
Natsume
K
K
Faculty of Computer Science and Systems Engineering, Kyushu Institute of Technology, Fukuoka, Japan.
Miyake
Y
Y
Yano
M
M
Shimizu
H
H
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002465:Cell Movement / Q000187:drug effects; D016839:Physarum polycephalum / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D013997:Time Factors
D002118:Calcium