A realistic model of rod photoreceptor for use in a retina network model
We propose a conductance-based model of a rod photoreceptor cell based on experimental data and other modeling works. In this model we use four types of ionic channels identified in the inner segment of the rod: nonselective cation channel (h), delayed rectifying potassium channel (Kv), noninactivating potassium channel (Kx) and calcium channel (Ca). The model accurately reproduces the rod response when fed with a simulated photocurrent signal. The results show that the initial transient in the voltage response is generated by the h channel. They also show that the h channel has a role in increasing the dynamic range of rod response to light intensity. Since we used a single compartment model and directly injected the photocurrent in this compartment instead of simulating the phototransduction process we produced a model with low computational cost to be used in large-scale retina models.
realistic modeling rod photoreceptor retina dynamic range ion channels