Inhibition of RA-signaling suppresses the proliferation of MGPCs in damaged retinas. Eyes were injected with a relatively high dose (500 nmol) of NMDA alone (control) or NMDA+RAR antagonist (BMS493) at P7, vehicle+EdU or RAR antagonist + EdU at P8 and P9, and tissues harvested at P10. Sections of the retina were labeled for EdU-incorporation and antibodies to Sox9 (green; a). The box plots illustrate the mean, upper extreme, lower extreme, upper quartile and lower quartile (n=7 animals). Significance of difference (*p<0.05) was determined by using a t-test. Arrows indicate the nuclei of MGPCs. The calibration bar (50 μm) in panel a applies to a alone. Abbreviations: INL – inner nuclear layer, IPL – inner plexiform layer, GCL – ganglion cell layer, ns – not significant.