Retinal ganglion cells (RGCs) were isolated using the two-step immunopanning protocol as previously described (Dvoriantchikova et al., 2012 (link)). Isolated RGCs were cultured in serum-free basal media (Neurobasal/B27 media; Life Technologies, Grand Island, NY) one day before the experiment. We obtained primary cortical astrocytes using the “shaking method” as previously described (Barakat et al., 2012 (link)). To prepare Müller glia, we used previously described protocol (Hauck et al., 2003 (link)). Briefly, retinas from early postnatal pups (P4–8) were digested for 30 minutes in papain (20U/ml), triturated and plated onto plastic dishes. Dishes were shaken after 16 hours and nonattached cells were removed. Attached Müller glial cells were grown until confluency, trypsinized and used in our study. Primary cortical astrocytes and Müller glia were cultured in Dulbecco’s Modified Eagle’s Medium (DMEM) (Life Technologies, Grand Island, NY), containing 10% heat-inactivated fetal bovine serum (FBS) (Life Technologies, Grand Island, NY) and 1% antibiotic/antimycotic (Life Technologies, Grand Island, NY). RGCs, astrocytes and Müller glia were maintained during the experiment in half DMEM and half Neurobasal media containing 0.1% FBS and 1% antibiotic/antimycotic.