Amacrine cells express little, if any, P-Rex2 in their processes and terminals. A-C: Confocal imaging of P-Rex2 and glutamic acid decarboxylase 65 kDa (GAD-65) labeling in the IPL. A: P-Rex2 labeling is present in discrete puncta located at all levels of the IPL (arrowheads). B: Labeling for GAD-65, a marker for GABAergic amacrine cells, labels numerous synapses and processes throughout the IPL. C: Overlay of panels A and B shows that P-Rex2 and GAD-65 are independently distributed. D-F: Confocal imaging of P-Rex2 and Glycine Transporter 1 (GlyT1) labeling in the IPL. D: Terminals at all levels of the IPL (arrowheads) show labeling for P-Rex2. E: Labeling for GlyT1 is present in glycinergic amacrine cell bodies (A) and processes throughout the IPL. F: Overlay of panels D and E confirms that P-Rex2 and GlyT1 show independent distributions. Single optical planes of approximately 0.3 μm thickness shown. Nuclei are counterstained with DAPI in panels A and D to illustrate the location of the INL and GCL. INL, inner nuclear layer; IPL, inner plexiform layer; GCL, ganglion cell layer. Scale bars = 10 μm for A-C; 20 μm for D-F.