A network thermodynamic model of ion transport in taste cells

Network thermodynamics is used for computer simulation of complex biological systems. The calculations are done on SPICE2. The sensation of taste is mediated by electrical events in taste bud cells embedded in the tongue epithelium. A model of the tongue epithelium was developed based on a network model of ion transport in a kidney epithelium. The model successfully simulates some aspects of both steady-state and time-dependent electrical measurements observed in the rat tongue when exposed to a wide range (50-2000 mM) of NaCl concentrations, the concentration range of interest for salt taste. The simulations lead to two main results. First, in a time-dependent analysis, in response to a prolonged hyperosmotic NaCl stimulus, the model predicts intracellular depolarization followed by repolarization. Second, steady-state calculations indicate that the Na⁺ channel in the luminal membrane of the taste cell must have different properties than those typical in similar epithelia