Retinal origin of cortical orientation map and its variation of spatial organization. A, Developmental model of orientation map as feedforward projection of ON and OFF retinal mosaics. Receptive field of a V1 neuron is organized from the local projection of ON and OFF retinal mosaics. B, The period of the retinal moiré interference pattern (scaling factor, S) is a function of the lattice spacing ratio (α) and the alignment angle (θ) between ON and OFF RGC mosaics. Orientation tuning of a V1 cell is decided from the local structure of ON and OFF RGC mosaics with feedforward wiring, thus the periodic retinal interference pattern seeds a cortical orientation map. Scale bar, S. C, Left, scaling factor S as a function of α and θ. Right, variation in the calculated value of S, when α is fixed to 0.094 as estimated from cat data (Zhan and Troy, 2000). D, Sample orientation maps developed by moiré interference of RGC mosaics for α = 0.094. Spatial period of maps appear to vary significantly for different value of θ Left, S = 11.7 of developed map for θ = 0°. Right, S = 3.8 for θ = 15°. Black arrows indicate spatial period of maps. Scale bar, 5d.