Figure 7. Modeling flash responses of frog rods and red-sensitive cones. The red lines are the experimental recordings; the black lines are the model responses. Black downward triangles show the beginning of a 1-ms stimulating flash. A: Suction pipette recording from a frog rod. The insert shows the initial part of the response on an expanded scale. The numbers at the curves indicate the relative intensities of 525-nm flashes. Intensity 1.0 corresponds to the fractional bleach of 1.6 × 10⁻⁵ per flash; average of 30 responses. B: Transretinal recording of the aspartate-isolated cone receptor potential; rod activity is suppressed by the 525-nm steady background. The stimulus is a 1-ms orange (longer than 600 nm) flash; fractional bleach 6.8 × 10⁻⁵ per flash; average of 100 responses. r is the coefficient of correlation between the experimental and model curves. Parameters of the fits are given in Table 2.