Figure 5.

Increased dark current in Line 379 R838S⁺ rods. A, B, Representative response families to flash stimuli recorded by suction electrode from a wild-type (A) and Line 379 R838S⁺ rods (B). Data were obtained at 4–4.5 weeks of age. Flash strength ranged from 1 to 3200 photons · μm⁻² with 0.5 log unit steps and flash duration was 2 or 20 ms. Bold traces represent the responses of the two rods to a flash of 32 photons · μm⁻². C, D, Intensity–response curves of wild-type (filled circles, ●) and Line 379 R838S⁺ (open diamonds, ♢) rods shown in absolute (C) or normalized (D) values. Data are shown as mean ± SEM, N = 11 (wild type) and 24 (R838S⁺). In D, the slope parameter n from the Naka–Rushton equation (fitting curves not shown) was not significantly different between wild type (1.20 ± 0.07) and R838S⁺ (1.23 ± 0.04); P value for two-tailed unpaired test was 0.74.