Adaptive behavior in ciliate that is a so-called swimming neuron

Abstract

A ciliate, Paramecium, is often called a swimming neuron as the electrophysiological studies done after 1960s have indicated the similar properties of membrane potential to that in neuron. A model equation for dynamics of membrane potential was proposed and is of Hodgkin-Huxley type that was originally proposed for squid neuron. Because ciliary motion that produces swimming force in ciliate is tightly regulated by the membrane potential, we expect that any kinds of behaviors, for instance, smart behaviors adaptive to environment, are organized by some modulation of model equation for membrane potential. Here we will introduce an adaptive behavior of a ciliate and discuss a possible mechanism of the adaptability based on the model equation for membrane potential.