A color coding amacrine cell may provide a “Blue–Off” signal in a mammalian retina

Retinal amacrine cells are thought to lack chromatic or color–selective light responses and play only a minor role in color processing. We now show that a type of mammalian (Ictidomys tridecemlineatus) amacrine cell selectively carries a blue–On signal, which is received from a blue or short–wavelength sensitive (S–) cone On bipolar cell. This glycinergic inhibitory “S–cone amacrine cell” is ideally placed for driving “blue–Off” responses in downstream ganglion cells.