A Novel Model of Electrical Action Potentials of Teleost Fish Ventricular Myocytes

Mathematical modelling, combined with experimental approaches, has become a powerful method for investigating the heart functions. So far, different models of cardiac electrical activities of variant species have been developed. However, models of fish cardiomycytes are less developed. Given the prominent problem of global warming, sea temperature changes will have a significant impact on the development of cardiac arrhythmias in the fish heart, leading to their sudden death, which may impose a heavy burden to the economy of the society. This study aimed to develop a biophysically detailed computer model for the teleost fish ventricular myocytes in warm acclimation (18 °C). A set of Hodgkin-Huxley (HH) formulations have been developed for the major ion currents that were based on experimental data from different teleost species. With a series of supra-threshold stimuli (amplitude of -41 pA/pF; duration of 10 ms and time interval (between two successive stimuli) of 1000 ms) the teleost fish model generates a successful sequence of action potentials (APs). The characteristics of the (APs) matched quantitatively the available experimental findings. In conclusion, a mathematical model for the electrical action potential of the teleost fish cardiac myocytes has been developed and validated.

1. Introduction

Cardiac modelling provides an alternative method to experimental cardiology for the study of the function of the heart. Since 1950s, a set of mathematical models for simulating cardiac membrane action potentials (APs) have been developed based on detailed experimental data on ion channel properties and kinetics, as well as intracellular ionic homeostasis [1], [2]. So far, a large set of cardiac cell models have been developed for variant mammalian species such as rat, mouse, sheep, rabbit and human, whereas mathematical models for fish heart has not been developed yet.