“…It is released by serotoninergic amacrine cells obtained in the retinas of many species (Ehinger 1983, Zhu et al 1992, Hurd and Eldred 1993, Gábriel 2000, Vigh et al 2000. Some serotonin-accumulating neurons are found among horizontal and bipolar cells, but it is thought that they are only able to transport and metabolize, but not synthesize serotonin (Marc et al 1988, Zhu et al 1992, Wilhelm et al 1993, Schutte 1994, Ghai et al 2009). Serotonin is also released by retinopetal axons that originate in dorsal raphe in fishes, rodents and primates (Villar et al 1987, Shen and Semba 1994, Lima and Urbina 1998, Gastinger et al 2005.…”