Figure 3. Deletion of multiple dopamine receptors does not alter photoreceptor cell survival in rd1 retinas in vivo. Retinas from D1^−/−, D2^−/−, rd1/rd1 (A), D1^−/−, D4^−/−, rd1/rd1 (B), D2^−/−, D4^−/−, rd1/rd1 (C) mice were harvested at postnatal day 21. The ONL of rd1/rd1 retinas was reduced to a monolayer of photoreceptors, regardless of DR genotype. Abbreviations: retinal pigment epithelium (RPE); outer nuclear layer (ONL); outer plexiform layer (OPL); inner nuclear layer (INL); inner plexiform layer (IPL); ganglion cell layer (GCL). The scale bar represents 10 μm.