SD rat RGC responses to drifting sinusoidal grating (15 lux mean illuminance) of various contrasts.

<p>(A) Contrast response function from a representative cell that displayed response saturation. (B) Contrast response function from a representative cell that did not displayed response saturation. (C) Contrast response function averaged from saturating RGCs (n = 57). (D) Contrast response function averaged from non-saturating RGCs (n = 59). Data points in (C) and (D) are the mean ± SEM (errors smaller than the symbol size are not visible). (E) Contrast thresholds for saturating and non-saturating RGCs. Boxes represent the interquartile range (IQR) between first and third quartiles and the line inside represents the median. Whiskers denote the lowest and highest values within 1.5 x IQR from the first and third quartiles. Circles represent all data points.