P2X2 receptors on ganglion and amacrine cells in cone pathways of the rat retina

Abstract

Extracellular ATP is known to mediate fast, excitatory neurotransmission through activation of ionotropic P2X receptors. In this study, the localization of the P2X2 receptor (P2X2R) subunit was studied in rat retina by using immunofluorescence immunohistochemistry and preembedding immunoelectron microscopy. The P2X2R was observed in large ganglion cells as well as in a subset of amacrine cells. Double labeling revealed that 96% of all P2X2R-immunoreactive amacrine cells showed γ-aminobutyric acid (GABA) immunoreactivity. Subsets of P2X 2R-immunoreactive amacrine cells expressed nitric oxide synthase and substance P; however, no colocalization was observed with choline acetyltransferase, vaso..