Excitatory currents in OFF ganglion cells are more rectified than those in ON ganglion cells. A, The stimulus was white noise followed by a constant intensity equal to the average of the white noise. B1, B2, Excitatory currents from ON and OFF ganglion cells, respectively (ON β and G5). The currents are displayed with their baseline subtracted (Ibaseline). Note that the current deflections for the OFF cell are inward (downward) of the steady currents evoked by the mean intensity (Isteady), whereas deflections for the ON cell are both inward and outward of Isteady, indicating that the OFF cell is more rectified than the ON cell. C1, C2, Impulse responses of the same ON and OFF cells. D1, D2, Static nonlinearities from the same ON and OFF ganglion cells. Note that the static nonlinearity for the OFF cell is more curved than that for the ON cell. The result is that almost the entire range of currents from the OFF ganglion cell is restricted to signaling negative contrast, but the currents from the ON ganglion cell are more evenly divided between positive and negative contrasts, confirming that the OFF cell is more rectified than the ON cell. n(0) is the current associated with zero contrast. E (top right of figure), Rectification index measured from static nonlinearities of 31 ON cells (15 ON β, 16 G2) and 33 OFF cells (7 OFF β, 20 G5, 6 LED). Error bars indicate SEM.