AII amacrine cells were visualized by injection of a recombinant adeno-associated virus serotype 2 (rAAV2) carrying a construct of green fluorescent protein (GFP) under control of a cytomegalovirus (CMV) promoter as previously described (Ivanova and Pan, 2009 (link)). The rAAV2 carries a Y444F capsid mutation for highly efficient vector transduction (Petrs-Silva et al., 2009 (link)). Briefly, mice aged postnatal day 30–60 (P30–60) were anesthetized by intraperitoneal injection of a mixture of 150 mg/kg ketamine and 15 mg/kg xylazine. Under a dissecting microscope, a small perforation was made in the temporal sclera region with a sharp needle. A total of 1.5 μl viral vector suspension in saline was injected into the intravitreal space through the perforation with a glass pipette (1B150F-4; WPI, Sarasota, FL) pulled with a P-97 Flaming/Brown puller (Sutter Instruments, Novato, CA). Viral vectors were packaged and affinity purified by Virovek (Virovek, Hayward, CA).