The code represents a computational model of a persistent sodium current (INaP) in retinal ganglion cells (RGCs). This current is modeled in a Hodgkin-Huxley style, which is a widely used approach in computational neuroscience to describe the ionic currents that flow through the membrane of neurons, based on the voltage across the membrane.
This model specifically simulates a persistent sodium current (INaP). Unlike transient sodium currents that activate and deactivate rapidly during action potentials, the persistent sodium current remains active at subthreshold voltages, affecting excitability and neuronal firing patterns over longer timescales.
p' = (p_inf - p)/tau_p
, where p_inf
is the steady-state activation level, and tau_p
is the time constant for reaching this steady-state.Tau and Activation Function: The tau_p
and p_inf
variables are calculated within the evaluate
procedure. They are determined by voltage-dependent activation and inactivation parameters (napp1 to napp8), derived from experimental data to fit the characteristics of sodium channel dynamics in RGCs.
Conductance (gnapbar): Represents the maximum conductance density of the channel, adjustable under different physiological conditions or modeling scenarios.
The persistent sodium current plays crucial roles in neuronal excitability, subthreshold oscillations, and overall network dynamics within the retina. By simulating this current, researchers can investigate how RGCs process visual information and respond to different stimuli, contributing to our understanding of visual perception and related disorders.