Modulation of the receptive field center response of cat retinal ganglion cells by the shift response signal through amacrine cells.

The effect of a stationary and an oscillating grating situated greater than 30 degrees from the RFC on the receptive field center response was examined. The transient firing rate of the center response was suppressed by the oscillating grating for all types of cells. The stationary grating also suppressed the transient firing but the degree of suppression was significantly less than that with the oscillating grating. There was also a significant elevation of the sustained firing rate in Y-cells. The on-going discharges were elevated in all types of units except on-center X-cells when the grating was oscillated. An increase in the area of a grating annulus did not increase the degree of suppression of the center response. This lack of spatial summation of the shift response was related to the properties of the on-off transient amacrine cells.