Excitatory effects of SRIF on the Ca2+ current in cones. A, Cones were held at −70 mV, and depolarizing pulses were applied from −40 to +40 mV in 10 mV steps. Responses were recorded in 20 mM Ba solution as described for Figure 5. Left, In control Ba Ringer’s solution. Middle, In 0.5 μM SRIF. Right, After a wash in Ba Ringer’s solution. B, Current–voltage plot of the data in A is shown. C, A summary of the changes induced in the peak Ca current of rods and cones by SRIF is shown. Cntr, Control (○), wash (△).