Related Experiment Video
Updated: Jul 19, 2026

Human Primary Trophoblast Cell Culture Model to Study the Protective Effects of Melatonin Against Hypoxia/reoxygenation-induced Disruption
Published on: July 30, 2016
Light, dark, and melatonin: emerging evidence for the importance of melatonin in ocular physiology
R Brennan1, J E Jan, C J Lyons
1Department of Ophthalmology, British Columbia Children's Hospital, Vancouver, British Columbia, Canada.
Abstract:
Melatonin is a hormone, which is mainly produced by the pineal gland, a vestigial eye. Rather than the rods and cones, it is a newly discovered subgroup of photosensitive retinal ganglion cells, which is responsible for mediating the light-dark cycles, thus regulating melatonin's secretion. One of the correlates of the circadian rhythm of melatonin release is the habitual sleep pattern. Patients with circadian rhythm sleep disorders, including some blind patients with no light-induced suppression of melatonin, benefit from melatonin treatment. Melatonin is synthesized in the retina, lens, ciliary body as well as other parts of the body. In this review, we discuss the physiological roles of melatonin in the eye, as well as the potential therapeutic avenues currently under study.
Related Concept Videos
The Pineal Gland
The primary secretion of the pineal gland is the hormone melatonin, derived from serotonin. The concentration of melatonin in the...
Management of Insomnia
Photoreceptors and Visual Pathways
Understanding Sleep
The circadian rhythm, a nearly 24-hour cycle, is deeply influenced by environmental light cues. Light exposure directly affects the hypothalamus, which in turn regulates...
Microbiome of the Eye
Circadian Rhythms and Gene Regulation