The expression of serotonin (5-HT) in the retina was first reported in the sixties. The
detection of vesicular monoamine transporter and serotonin receptors in several retinal cells
confirm that 5-HT is playing a neuromodulatory role in this structure. Whereas signaling
pathways activated by 5-HT receptor binding has been poorly investigated so far, numerous
data demonstrated that 5-HT is involved in retinal physiology, retinal physiopathology and
photoreceptor survival.