Fig. 4.

Effect of strychnine and TTX on the waveform of the response elicited by center illumination. The traces show superimposed responses of a tiger salamander on–off ganglion cell to a 400-μm-diameter spot (8.4 log quanta) in the receptive field center in control Ringer’s solution, in the presence of 2 μmstrychnine (STR), and in the presence of 500 nm TTX. Each trace is the average of eight responses. The retina was washed with control Ringer’s solution for 20 min between the two drug applications. Resting potential was −55 mV in all traces.