Figure 2.

Temporal relationship between excitatory and inhibitory synaptic inputs differs for midget and parasol cells. A, Simplified circuit for excitatory and inhibitory synaptic inputs to On midget ganglion cells highlighting those cells producing excitatory (blue) and inhibitory (red) synaptic inputs. B, On midget cell responses to light steps. Left, Average synaptic currents and spike response to a 100% contrast light step. Right, Average synaptic conductances. Inset shows responses to the step onset on an expanded time scale. Calibration: 1 nS, 0.1 s. C, On midget cell responses to sinusoidal stimuli. Left, Currents and spike response to 4 Hz temporally modulated full-field stimulus. Right, Average conductances and spike responses during one cycle of the stimulus. D–F, Simplified On parasol circuit and responses as in A–C.