Modeling and simulation of vertebrate primary visual system: Basic network

Neuronal activities in the primary visual system in vertebrates were studied by mathematical modeling and simulations. The eight-cell model, called the basic network, is governed by eight coupled nonlinear integro-differential difference equations. Five of the cells in the basic network are from the retina, and the remaining three are from the lateral geniculate nucleus and the visual cortex, forming a functional unit to process the visual information. This functional unit has two local circuitries, the retinal pathway and the thalamocortical pathway, connected by the optic nerve. Each cell in the basic network is characterized by its structure and interaction with other cells. The modeling of the basic network is described. The system equations are derived from the more general neuronal network equations by taking into account the main characteristics of the neurons, the form of the connections, and the manner of the interactions. The experimental determination of the system parameters is briefly discussed. A specific parametric configuration is introduced for a reference framework in the discussions. The simulations are considered under different conditions, as well as the responses of the system to certain rectangular and periodic incoming light intensities.