Chicken retinas were exposed to intravitreal kainic acid to destroy amacrine and bipolar cells at low concentrations, and horizontal cells at high concentrations in addition. Ganglion cells were destroyed by intravitreal injections of colchicine. Low doses of kainic acid reduced the number of binding sites for both 3Hquinuclidinyl benzilate (muscarinic acetylcholine receptors) and N-propionyl3Hα-bungarotoxin (nicotinic acetylcholine receptors), with little additional loss at higher doses. In contrast, colchicine reduced the number of binding sites for N-propionyl-3Hα-bungarotoxin, but had little or no effect on the number of binding sites for 3Hquinuclidinyl benzilate. These results are consistent with the idea that, in chicken retina, cholinergic amacrine cells make contact with ganglion cell dendrites at sites which possess mainly nicotinic acetylcholine receptors, while both types of receptor are involved in interactions between amacrine cells and perhaps bipolar cell
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