A Mathematical Modeling Study of Dopaminergic Retinal Neurons under Hyperpolarized Conditions

摘要

A mathematical model of dopaminergic local circuit neurons isolated from the mouse retina (DA cells) was previously reported. This DA cell model was constructed based on the Hodgkin-Huxley formalism and is described by a system of nonlinear ordinary differential equations. The DA cell model contains four voltage-dependent ionic conductances: persistent sodium conductance, transient sodium conductance, fast potassium conductance, and slow potassium conductance. The present study involved a numerical simulation analysis of the DA cell model under hyperpolarized conditions to characterize these four ionic conductances. The analysis revealed a novel mechanism of repetitive spiking under hyperpolarized conditions. This mechanism contributes to the in-depth understanding of sodium conductances in DA cell models.