Investigate Channel Rectifications and Neural Dynamics by An Electrodiffusive Gauss-Nernst-Planck Approach

Electrodiffusion plays a crucial role in modulating ion channel conductivity and neural firing dynamics within the nervous system. However, its influence on neural function remains underexplored. In this work, we introduce a novel Gauss-Nernst-Planck (GNP) approach to investigate how electrodiffusive dynamics influence ion channel rectification and neural activity. For the first time, we demonstrate that membrane conductivity is determined by both ion permeability and the harmonic mean of intramembrane ion concentration, bridging the gap between the permeability-based Goldman-Hodgkin-Katz (GHK) model and conductance-based models. We characterize the rectification properties of GABAA, AMPA, and leaky channels by estimating their single-channel permeabilities and conductance. By integrating these rectifying channels into neurodynamic models, our GNP neurodynamic model reveals how electrodiffusive dynamics fundamentally shape neural firing by modulating membrane conductance and the interplay between passive and active ion transport-mechanisms that are often overlooked in conventional conductance-based neurodynamic models. This study provides a fundamental mechanistic understanding of electrodiffusion regulation in neural activity and establishes a robust framework for future research in neurophysiology.