melanopsin


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Related to melanopsin: photopigment

melanopsin

An opsin-like protein, sensitive to light with a peak sensitivity around 480 nm, and found in the very small proportion of retinal ganglion cells which are photosensitive. It is believed to be the visual pigment that synchronizes the circadian cycle to the day-night cycle as well as being involved in the control of pupil size and the release of melatonin. This neural circuit appears to be independent of the conventional retinal phototransduction in the rods and cones. See pupil light reflex.
References in periodicals archive ?
Melanopsin (Opn4) requirement for normal light-induced circadian phase shifting.
Previous research has shown that relative to unaffected peers, people with SAD have a reduced melanopsin cell response in winter (Psychiatry Res.
In the December 2001 issue of Nature Neuroscience, Josh Gooley, then a first-year Harvard graduate student, showed in rats that melanopsin cells connect to the SCN.
This study clarifies the role of melanopsin in setting and maintaining the circadian clock," said Bruce O'Hara, senior research scientist at Stanford and co-author of the study published in the Dec.
Melanopsin is required for non-image-forming photic responses in blind mice.
The team of experts from the University of Manchester and Imperial College London found that activating melanopsin in cells that don't normally use the gene makes them sensitive to light.
When stimulated, the cells trigger the release of an "alertness" hormone, melanopsin.
The researchers suggest that body temperature and heart rate may be regulated by retinal cells that contain a light-sensitive protein called melanopsin.
His research in the Laboratory of Regulatory Biology revealed that melanopsin not only reports the intensity of incoming light to the circadian clock but also to regular visual centers in the brain.
After injecting dyes into the eye, they traced the path of the melanopsin retinal cells through the optic nerve to the brain, where they found a group of neurons that become electrically active during migraine.
15 JOURNAL OF NEUROSCIENCE, they report finding the human version of the protein and reveal that melanopsin is made by cells in the eye's inner retina.