A guinea pig antibody against the RNA binding protein with multiple splicing (RBPMS, #1832-RBPMS, RRID: AB_2492226; PhosphoSolutions, Aurora, CO, USA) was used to label all retinal ganglion cells.16 (link) A mouse monoclonal antibody against calmodulin-dependent protein kinase II (CaMKII, #ab22609, clone 6G9, RRID: AB_447192; Abcam, Cambridge, UK) was used to label CaMKII-expressing ganglion cells.17 (link) Two monoclonal antibodies against GABAA receptor subunits (bd17 alpha chain; bd24 beta 2,3 chain; Boehringer Mannheim, Mannheim, Germany) were used to label foveal parasol cells.18 (link),19 (link) Retinal flat-mount preparations and vibratome sections through the central retina were prepared and processed as described in detail previously.17 (link),19 (link)