Two-Segment Electophysiological Model of Excitable Membrane of Paramecium

Our goal in this paper is to design a two-segment electrophysiological model for Paramecium based on the work of Hook and Hildebrand (1979, 1980). This model considers Paramecium divided into two segments. Both segments are assumed to obey Hook and Hildebrand equations. The aim of constructing this model is to consider theoretically how the free- swimming Paramecium responses to the external electric stimulation, involving whether the organism is facing the anode or the cathode during the application of the electric pulse. We assume that there is an irregular distribution of Ca^2+ and K^+ channels on both segments. We have designed a computer program to illustrate the relationship between the distribution channels and swimming reversal time of the Paramecium. It is found that the reversal time depends on the precise distribution of Ca^2+ and K^+ channels. The relevant ratio of ionic channels distribution is found to be 74.8% and 25.2% for K^+ and Ca^2+, respectively over the cell anterior and vice versa for posterior.