Contractile system of muscle as an auto-oscillator

Shin'ichi Ishiwata*, Yuta Shimamoto, Norio Fukuda

*Corresponding author for this work

    Research output: Contribution to journalArticlepeer-review

    34 Citations (Scopus)


    It is widely known that the contractile system of muscle takes on either the state of contraction (force-generating) or the state of relaxation (non-force-generating), which is known as the " all-or-nothing" principle. However, it is important to note that under intermediate activation conditions there exists a third state, which demonstrates auto-oscillatory properties and is termed SPOC (SPontaneous Oscillatory Contraction) state. We present a phase diagram, in which the states of the contractile system of muscle are divided into three regions consisting of contraction, relaxation and SPOC states. In the present review, experimental data related to the characteristics of SPOC are summarized and the mechanism of SPOC is described. We propose that the bio-motile system itself is an auto-oscillator, even in a membrane-less supra-molecular structure composed of an assembly of molecular motors and cytoskeletons (actin filaments and microtubules). Finally, the physiological significance of SPOC is discussed.

    Original languageEnglish
    Pages (from-to)187-198
    Number of pages12
    JournalProgress in Biophysics and Molecular Biology
    Issue number3
    Publication statusPublished - 2011 May


    • Auto-oscillation
    • Cardiac muscle
    • Myofibril
    • Sarcomere
    • Skeletal muscle
    • SPOC

    ASJC Scopus subject areas

    • Molecular Biology
    • Biophysics


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