Fig. 1.

Flash-response families of monkey and other mammalian cones. (A–C) Flash-response families of a monkey L-, M-, and S-cone (Left), with corresponding intensity–response relations at transient peak of response (normalized by the saturated response, R_max; Right). Curve fits are with a saturating-exponential function (Materials and Methods). The half-saturating flash intensity, σ, is 2,114, 2,634, and 1,831 photons⋅μm⁻², respectively, at near corresponding λ_max values (Materials and Methods). (D) An L-cone showing biphasic responses, with σ being 1,765 photons⋅μm⁻² at near λ_max. (A) Outer-segment recording; (B–D) inner-segment recordings. (E–H) Flash responses of pig, ground squirrel, Nile grass rat, and mouse cones (Left), with corresponding normalized intensity–response relations (Right) having σ values of 1,006, 20,700, 24,900, and 5,020 photons⋅μm⁻², respectively, at near corresponding λ_max values (Materials and Methods). In all cases, flash is at time 0, and traces are averages of 2 to 15 responses.