The fovea of a mammal retina was simulated with its detailed biological properties to study the local preprocessing of images. The direct visual pathway (photoreceptors, bipolar and ganglion cells) and the horizontal units, as well as the D-amacrine cells were simulated. The computer program simulated the analog nonspiking transmission between photoreceptor and bipolar cells, and between bipolar and ganglion cells, as well as the gap-junctions between horizontal cells, and the release of dopamine by D-amacrine cells and its diffusion in the extra-cellular space. A 64 × 64 photoreceptors retina, containing 16,448 units, was carried out. This retina displayed contour extraction with a Mach effect, and adaptation to brightness. The simulation showed that the dopaminergic amacrine cells were necessary to ensure adaptation to local brightness.
['Eric Boussard', 'Jean-François Vibert']
Dopaminergic Neuromodulation Brings a Dynamical Plasticity to the Retina