Simulation of cell activities in pharyngeal pumping in

線虫の咽頭ポンピングにおける細胞活動シミュレーション

服部 佑哉; 鈴木 芳代; 曽 智*; 小林 泰彦; 辻 敏夫*

Hattori, Yuya; Suzuki, Michiyo; Soh, Zu*; Kobayashi, Yasuhiko; Tsuji, Toshio*

shows some rhythmic movements including the pharyngeal pumping motion for chewing and swallowing. Biological signals can be measured using the electropharyngeogram (EPG), which represents the electrophysiological responses of the pharyngeal muscle cells in a lump, and there is evidence that the pumping rhythms are generated by the pharyngeal muscle cells and controlled by pharyngeal neurons. In addition, we recently reported that the pumping rhythms temporarily change after ionizing irradiation. Thus, the pumping motion in is considered a useful system to investigate the rhythmic phenomena. However, it is difficult to measure the membrane potentials of individual cells, and the mechanisms of rhythm generation and control in pharynx are not well understood. In this study, we propose a simulation-based approach to investigate the mechanisms of rhythm phenomena. To conduct the simulations, we developed a pharyngeal muscle model including 29 cell models, which simulate the activity of each cell as a membrane potential based on the FitzHugh-Nagumo equations. Subsequently, we calculated the EPG by using the outputs of all cell models. As the result, our model successfully generated similar EPG to that observed in a wild type. Furthermore, we could simulate the responses of some mutants such as mutant by ablating certain gap junctions virtually so as to correspond to the defects.