Colocalization of [3H]muscimol uptake and choline acetyltransferase immunoreactivity in amacrine cells of the cat retina.

High affinity uptake of [3H]muscimol, a gamma-aminobutyric acid (GABA) analogue, followed by autoradiography, labelled practically all amacrine cells which expressed GABA-like immunoreactivity. Hence it is a good marker for putative GABAergic amacrine cells. All amacrine cells, which were stained with antibodies against choline acetyltransferase, a marker for cholinergic neurones, also accumulated [3H]muscimol. This makes it likely that cholinergic amacrine cells of the cat retina are a subpopulation of putative GABAergic amacrine cells.