The role of the bipolar cell in retinal signal processing

Bipolar cells in the retina of the tiger salamander were studied by intracellular recording. Their receptive fields consisted of a central region and a surround which, when stimulated, antagonized the response of the center. The spatial distributions of the center and surround components were determined, using drugs that selectively eliminated the surround. The receptive field is shown to be a linear combination of the two components. Because of the spatial antagonism the receptive field acts as a bandpass spatial filter. The importance of this filtering in photon detection is discussed