Circadian Health Glossary
Melanopsin
Melanopsin is a light-sensitive protein found in intrinsically photosensitive retinal ganglion cells (ipRGCs) in the eye. Unlike rods and cones, which are responsible for vision, melanopsin detects light primarily to regulate circadian rhythms and other non-visual processes.
How Does Melanopsin Work?
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Blue Light Sensitivity: Melanopsin is most responsive to blue light (wavelengths around 480 nm), which makes it crucial for aligning the body’s internal clock with the external environment.
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Circadian Regulation: Signals from melanopsin-expressing cells travel to the brain’s suprachiasmatic nucleus (SCN), the body’s master clock, helping to regulate sleep-wake cycles, alertness, and hormone production.
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Pupillary Light Response: Melanopsin also controls the pupillary light response, causing the pupils to dilate or constrict based on light intensity as a protective mechanism. Additionally, melanopsin may influence mood and cellular behavior across different seasons.
Why Is Melanopsin Important?
- Circadian Health:Plays a key role in synchronizing the body’s internal rhythms with natural light-dark cycles.
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Light Therapy: Devices designed to regulate circadian rhythms often target melanopsin sensitivity for maximum effectiveness.
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Sleep and Mood: Proper melanopsin stimulation improves sleep quality and mood, while insufficient stimulation can lead to circadian misalignment.
Understanding melanopsin is essential for advancing technologies like light therapy and improving overall circadian health.