Cone receptive field in cat retina computed from microcircuitry.

The receptive-field profile of the cone in cat-retina was computed. The computation was based on (1) the known anatomical circuit connecting cones via narrow-field bipolar cells to the on-beta ganglion cell; (2) the known physiological receptive-field profile of the on-beta (X) cell at the corresponding eccentricity; and (3) a model in which the beta receptive field arises by linear superposition of cone receptive fields. The computed cone receptive field has a center/surround organization with a center almost as broad as that of the beta cell center. The cone surround is comparably broad to that of the beta cell but somewhat lower in peak amplitude. The problems to which the center/surround receptive field are the solution, namely, signal compression and noise reduction, apparently must be solved before the first synapse of the visual pathway.