title: Calcium wave for cytoplasmic streaming of Physarum polycephalum.
abstract: The plasmodium Physarum polycephalum exhibits periodic cycles of cytoplasmic streaming in association with those of contraction and relaxation movement. In the present study, we injected Calcium Green dextran as a fluorescent Ca2+ indicator into the thin-spread living plasmodium. We found changes in the [Ca2+]i (intracellular concentration of Ca2+), which propagated in a wave-like form in its cytoplasm. The Ca2+ waves were also detected when we used Fura dextran which detected [Ca2+]i by the ratio of two wavelengths. We prepared the plasmodial fragment from the thin-spread and found that the cycles of the contraction-relaxation movement was so synchronized that the measurement of its area provided an indication of the movement. We observed that [Ca2+]i also synchronized in the entire fragment and that the relaxation ensued upon the reduction in [Ca2+]i. We suggest that the Ca2+ wave generated periodically is one of the major factors playing a crucial role in the relaxation of P. polycephalum.
authors: Department of Biology, Faculty of Education, Shiga University, Otsu, Shiga 520-0862, Japan.
authors: Shinji
authors: S
authors: Yoshiyama
authors: Mitsuo
authors: M
authors: Ishigami
authors: Akio
authors: A
authors: Nakamura
authors: Kazuhiro
authors: K
authors: Kohama
mesh_terms: D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling; D003595:Cytoplasmic Streaming; D003911:Dextrans / Q000494:pharmacology; D005456:Fluorescent Dyes / Q000494:pharmacology; D009068:Movement; D009930:Organic Chemicals / Q000494:pharmacology; D010507:Periodicity; D016839:Physarum polycephalum / Q000378:metabolism / Q000502:physiology*
chemical_list: D003911:Dextrans; D005456:Fluorescent Dyes; D009930:Organic Chemicals; C071336:calcium green; D002118:Calcium