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How does ocular melatonin influence pineal melatonin at night?

Discussion in 'The Cave' started by Curves, Nov 12, 2015.

  1. Curves

    Curves Guest

    I'm trying to get a better grasp of the relationship between retinal/ocular melatonin and pineal melatonin.

    I know UV light hits the retina in the morning making ocular melatonin and turning off production of pineal melatonin.

    What I'm wanting to know more about is how does ocular melatonin influence the production of pineal melatonin at night. Quoting you from the Health and Wellness Show "The latest research in probably the last 8 or 9 years shows that full spectrum sunlight in the morning actually increases ocular melatonin. Without ocular melatonin made in the eye, you cannot release pineal melatonin after four hours of darkness. "

  2. Jack Kruse

    Jack Kruse Administrator

  3. Jack Kruse

    Jack Kruse Administrator

  4. Jack Kruse

    Jack Kruse Administrator

  5. Jack Kruse

    Jack Kruse Administrator

  6. Jack Kruse

    Jack Kruse Administrator

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    Jack Kruse Administrator

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    Jack Kruse Administrator

  9. Jack Kruse

    Jack Kruse Administrator


    Melatonin concentrations decreased 10 to 20 minutes after the subjects were exposed to 2500-lux incandescent light and reached near-daytime levels within 1 hour (Fig. 1). After the subjects resumed sleeping in the dark, the melatonin concentrations increased immediately and within 40 minutes were at the levels measured before exposure. The fluorescent light (500 lux) did not reduce melatonin, and there was no change after the return to darkness. In the two subjects who were exposed to 1500-lux incandescent light, melatonin concentrations decreased to levels intermediate between those measured during exposure to 500 and 2500 lux (Fig. 2). The return to normal nighttime concentrations after subjects were exposed to 1500 lux was similar to that occurring after their exposure to 2500 lux. The concentration of melatonin in subjects awakened and exposed to 500-lux fluorescent light did not differ significantly from that measured while they were asleep in the dark.
    seanb4 and Joe Gavin like this.
  10. Josh Rosenthal

    Josh Rosenthal Charter member of Purple Angels Club

  11. Josh Rosenthal

    Josh Rosenthal Charter member of Purple Angels Club

    does this imply that 500 lux is the threshold for melatonin suppression?
  12. Jack Kruse

    Jack Kruse Administrator

    Yep. Pretty damn low.
  13. Curves

    Curves Guest

    Thank you. Happy Dancing. I know what I'll be doing all day today!
  14. Lahelada

    Lahelada New Member

    500 lux = 500 lumens over an area of a square meter
    You cannot make that calculation add up though as this would mean that melatonin is not affected when sleeping with a 60 w CFL considering an average size bedroom of 14sqm or 150 sqft.
    While that is low lighting in interior design terms surely it is still too much? You could read by that light.
    For reference full moon light is 0.25 lux roughly,full daylight 2000 lux.
    Are they confused with the lumen specification that manufacturers do put on the package?
    Someone check my maths please as it is important for the red/ purple light overnight biohackers.
    Curves likes this.
  15. Curves

    Curves Guest

    Tying some pieces together:

    · Melatonin is a hormone, which is mainly produced by the pineal gland, a vestigial eye. . . . very rarely are we reminded of its phylogenetic origin as the third eye . . .
    · This very ancient molecule exists in organisms as simple and primitive as prokaryotes and as complex as humans.2 It acts as a free radical scavenger and an antioxidant, possibly its initial function 2–3.5 billion years ago.
    · The retina has a light-mediated feedback system; melatonin mediates darkness-related adaptive changes, and dopamine mediates light-related changes.
    · Dopamine has the opposite effect to melatonin and can mimic light in entraining and phase shifting the circadian oscillator which controls melatonin rhythmicity

    Still not yet understanding the causal relationship between ocular daytime melatonin and pineal nightime melatonin. Do they aggregate? Do different things? Signal each other? Scientific third grader here still trying to piece the puzzle together.
  16. Curves

    Curves Guest

    @Lahelada I surely won't be the one to confirm your math :) but this study says it's < 200 lux. This still seems high to me considering the retina responds to 5 photons of light. I bolded the area in the abstract that I found interesting with respect to this discussion.



    Photic Regulation of Melatonin in Humans: Ocular and Neural Signal Transduction
    1. George C. Brainard

    1. Department of Neurology, Thomas Jefferson University, Jefferson Medical College, Philadelphia, PA 19107
    1. Mark D. Rollag

    1. Department of Anatomy, Uniformed Services University of Health Sciences, Bethesda, MD 20814
    1. John P. Hanifin

    1. Department of Neurology, Thomas Jefferson University, Jefferson Medical College, Philadelphia, PA 19107

    Light is a potent stimulus for regulating the pineal gland's production of melatonin and the broader circadian system in humans. It initially was thought that only very bright photic stimuli (≥ 2500 lux) could suppress nocturnal melatonin secretion and induce other circadian responses. It is now known that markedly lower illuminances (≤ 200 lux) can acutely suppress melatonin or entrain and phase shift melatonin rhythms when exposure conditions are optimized. The elements for physical/biological stimulus processing that regulate photic influences on melatonin secretion include the physics of the light source, gaze behavior relative to the light source, and the transduction of light energy through the pupil and ocular media. Elements for sensory/neural signal processing become involved as photons are absorbed by retinal photopigments and neural signals are generated in the retinohypothalamic tract. Aspects of this physiology include the ability of the circadian system to integrate photic stimuli spatially and temporally as well as the wavelength sensitivity of the operative photoreceptors. Acute, light-induced suppression of melatonin is proving to be a powerful tool for clarifying how these elements of ocular and neural physiology influence the interaction between light and the secretion of melatonin from the human pineal gland.

    Joe Gavin, Scompy and Lahelada like this.
  17. Lahelada

    Lahelada New Member

    I had only read the science direct article Jack quoted . however 200 lux is still 800 times full moon light.
    I personally would read it as lumens and then it would be a 10 w bulb which seems more in tune with what we have learned so far. I questioned it as I needed to learn the lumen lux and watts equivalent and in every page I found 500 lux to be a high lighting level . Of course distance and placement comes into it as well.
    Curves likes this.
  18. Curves

    Curves Guest

    Is this it @Jack Kruse ? "In the retina, melatonin plays an important role in switching the retina from a light-adapted to a dark-adapted state at dusk by suppressing dopaminergic function."

    For this reason · Dopamine has the opposite effect to melatonin and can mimic light in entraining and phase shifting the circadian oscillator which controls melatonin rhythmicity

    @Josh Rosenthal is this what you were referring to?

    https://books.google.com/books?id=m_6okSRjzloC&pg=PA298&lpg=PA298&dq=relationship between retinal melatonin and pineal melatonin&source=bl&ots=mLje4KIoHH&sig=brtSm8cZnBmFrz3ckj0xbzxhmS4&hl=en&sa=X&ved=0CD0Q6AEwA2oVChMIzJfs4ceOyQIVFFRjCh2PCA3N#v=onepage&q=relationship between retinal melatonin and pineal melatonin&f=false
    Lahelada and thisbirdhaswings like this.
  19. Penny

    Penny New Member

    that was the most fantastic interview of all time! And it's a transcript - with links! Heaven!
    thisbirdhaswings and Curves like this.
  20. Jack Kruse

    Jack Kruse Administrator

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