Figure 5.
Gain, noise, and threshold of mouse on α ganglion cells. A, Dependence of gain on background. Collected current responses (mean ± SEM) from mouse on α ganglion cells in slice (N = 16; filled circles) and in flat-mount (N = 13; open circles) preparations. Smooth fit from Equation 5: exponent m = −0.78 ± 0.05 for slice, −0.62 ± 0.05 for flat mount (mean ± SD); a = 0.01 for slice and 0.19 for flat mount; b fixed at 1.3; c = 2.91 for slice and 2.44 for flat mount; and d fixed at 1. Voltage clamped at −60 mV. B, Dependence of flash-independent noise on background. Smooth fit from Equation 5 with a fixed at 10, b fixed at 1.6, c = 0.003, d = 0.007, and m fixed at −1. C, Dependence of flash-dependent noise on background. Smooth fit from Equation 5 with a = 0.74, b fixed at 1.3, c = 0.68, d = 0.09, and m = −0.54. D, Dependence of threshold on background for mouse (black) and primate (gray). Smooth fit to the mouse data from Equation 6 increased with M = 0.76 ± 0.08 (mean ± SD), ID = 0.29, and K = 0.02.