Why green light helps reduce pain in mice (Activates opioid receptors)

Medical Xpress / Science Translational Medicine ^ | Dec. 8, 2022 | Bob Yirka / Yu-Long Tang et al

[ConservativeMind]

A team of researchers has traced neural activity from the eyes to the brain in mice to find out why green light helps to reduce pain. In their paper, the group describes studying each part of the visual neural system in mice, from the back of the eyes to the brain, to learn more about how light can impact sensations in the brain.

Prior research and anecdotal evidence have suggested that green light, particularly green light generated by LEDs, can reduce pain levels in people with conditions such as arthritis, migraines and fibromyalgia—but the reasons have remained a mystery. In this new effort, the researchers sought to find the answer.

The researchers studied all of the parts of the visual processing system in mice that are involved in receiving and processing light. They began with the rods and cones photoreceptors on the outer part of the retina and retinal ganglion cells (ipRGC) in the inner part of the retina. By disabling each at different times and then testing how they led to changes in pain experience, the researchers found that the neural pathway to pain relief began with the photoreceptors.

The team then moved on to retinal ganglion cells, which receive signals from the photoreceptors. They used genetic silencing to learn more about which of the cells was responsible for communicating with the ventral lateral geniculate nucleus in the thalamus.

Next, the team monitored such signaling as different colors of light were directed into the eyes of the mice and found that green light resulted in more GABA signaling, which resulted in more expression by the Penk gene which encodes for a protein called PENK. And PENK is a precursor for a molecule called ENK, which activates opioid receptors in the brain. And that leads to the dulling of pain.

[Tunehead54]

"Perhaps we feel better, when looking at grass, because our bodies are coded to dull pain from it."

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Unfortunately, because it's well established that the grass is always greener on the other side of the fence, your jealousy of your neighbor's superior lawn, negates any positive benefit of the green grass and all your emotions of jealousy, rage, inadequacy, etc. probably completely overwhelms any transient "feel good" benefit from the color green.

Still I'm getting my wife a green night light for Christmas!

Happy wife, happy life. ;-)

PS: Thanks so much for all your interesting medical posts and hard work.

Merry Christmas (unless that's offensive) and please have a happy new year. We could use one.

[Carriage Hill]

Better deal.

[ConservativeMind]

Thank you, sir, and it was appropriate and not offensive, in any way.

[jmacusa]

The human eye can detect more shades of green than any other color.

[steve86]

Consider getting bupropion (Wellbutrin) from another source like I do and making a drug comparable to Contrave by combining with naltrexone. I am interested in hearing your experiences so please keep in touch. Steve

[RummyChick]

I have that on hand but have never taken it I will give the combo a try.

[steve86]

The bupropion is generally a fairly well-behaved drug for most people. Not likely to cause you much trouble.

[steve86]

(as long as you have no history of seizures)

[steve86]

I actually have Rx for both. Just making that clear here. The bupropion is even covered by my insurance.

[steve86]

For anyone interested.... This is what we’re talking about ... Not exclusive to fibro, though.

https://www.verywellhealth.com/low-dose-naltrexone-ldn-for-fibromyalgia-cfs-716070