A mathematical model of human oesophageal motility function

Recent advances in various observation methods revealed several unique characteristics of oesophageal peristalsis and its disorders. However, a framework for understanding the oesophageal motility pattern is lacking. Here, we propose a simple mathematical model of the human oesophageal motility function. The model comprises central nervous system signals, enteric nervous system neurons (interneurons and motoneurons) and oesophageal smooth muscles. The neural function implements excitable dynamics at the oesophageal body and toggle-switch dynamics at the lower oesophageal sphincter. The local signal transmission in enteric nervous system and 'the law of the intestine' were also incorporated. The model behaviours can be understood using mathematical analysis, and we could reproduce the physiological dynamics of the normal oesophagus-deglutitive inhibition, unidirectional pulse transmission, restoration of lower oesophageal sphincter constriction and dilatation of the anal side of the pulse. In addition, we could reproduce various pathological motility patterns described in the Chicago classification by the combinations of parameter changes, which may provide insights into the possible pathogenesis of these disorders.