Answer Happy

You are recording from an ON-center ganglion cell. During your experiment the cell is not firing any action potentials. How is this possible? This is because there is no light stimulus in the receptive field of this ganglion cell This is because you made the surround of this ganglion cell's receptive field darker than the center. This is because the entire receptive field of this ganglion cell is covered with light This is because the visual field is in complete darkness, thus ganglion cells are inactive, This is because you made the surround of this ganglion cell's receptive field is brighter than the center.