Hierarchical organization of noise generates spontaneous signal in Paramecium cell

In many cellular processes, spontaneous activities are often the basis for their functioning. Paramecium cells change their swimming direction under a homogeneous environment, which is induced by a spontaneous signal generation in the membrane electric potential. For such a spontaneous activity, a theoretical model has been proposed by Oosawa (2007) [Biosystems 88, 191–201.], in which intracellular noise is hierarchically organized from thermal fluctuations to spike-like large fluctuations, which induces a signal to change spontaneously the swimming direction. Our analysis of the model shows that the system is a kind of excitable media, in which a spike is induced by a stochastic fluctuation. We show conditions of channels properties to have a spike train.

► We study spontaneous signal generations in Paramecium cells to switch run direction.
► In the model, noise is organized from molecular to membrane potential fluctuations.
► The system is a kind of excitable media with spikes induced by stochastic noise.
► We show conditions of channels properties to have a spike.