The effects of strychnine and bicuculline on the responses of X- and Y-cells of the isolated eye-cut preparation of the cat.

The effects of strychnine and bicuculline, the respective antagonists of glycine and GABA, on the inhibitory responses of X- and Y-type retinal ganglion cells of the cat were investigated using an isolated eye-cup preparation. The surround inhibition of the on-center X-cell was blocked by strychnine, whereas that of the on-center Y-cell was blocked by bicuculline. In the case of the off-center cells, bicuculline indifferently blocked the center and the surround responses of either the X-cell or the Y-cell, but strychnine did not.