Figure 4. Effect of Cs⁺ on τ_D.

(A) Response family to flashes of light in HEPES-buffered Ringer containing 2 mM aspartate. Flash strengths: 140, 278, 441, 880, 1394, 2780, 4400, 7000 Rh*. (B) Response family to identical set of flashes as in A from the same retina after addition of 5 mM Cs⁺ to perfusion. (C) Identical stimulus set as in A and B when retina was exposed to low 25 nM free Ca²⁺ with 5 mM Cs⁺ present. Horizontal lines indicate the data points used in D. (D) Determination of τ_D from A (▪), B (blue ▴) and C (red ○).τ_D was 370, 300, 812 ms in Ringer, 5 mM Cs⁺ and in low Ca²⁺ with 5 mM Cs⁺, respectively.