The Mechanism of Sleep and Wakefulness: The Roles of the Pineal Gland and Melatonin
Posted by 良請川
Did you watch the TV show "Heaven and Hell: Psychotic Two", starring Haruka Ayase, which aired in 2021?
It's a story where the souls of a desperate female detective and a psychopathic murderer are swapped.
When I saw the names of Ayako Mochizuki (played by Ayase) and Haruto Hidaka (played by Issey Takahashi), I thought, "Aha, I see, there are many meanings embedded here."
What do you think?
1. Sun and Moon are Always in Contrast
Moon and Sun
In the first place, everything in heaven and earth is interchangeable.
This includes heaven and hell, good and evil, and the sun and moon.
When the Kanji characters for "日" (sun) and "月" (moon) are combined, they form "明" (bright), but things don't always go as planned in the world.
Various contrasts exist, sometimes it's a bright, sunny smile vs. a quiet, watchful presence like the moon. In this show, it's a complex interplay of full moon (Mochizuki) vs. new moon (Saku, the first day of the old calendar), detective vs. criminal, woman vs. man, older brother vs. younger brother, and so on.
An incident occurs on the night of the new moon, and the symbol "φ (phi, empty set)" appears.
Both "saku" and "φ" signify "a start from 0 or 1".
Speaking of which, the legend of werewolves transforming on the night of a full moon has been famous since ancient times.
Animals are inherently keen at sensing the Earth's magnetism, gravity, atmospheric pressure, etc.
However, humans, who evolved from animals, have had these sensors dulled.
The moon's gravity significantly affects living organisms and tides, as shown in the following diagram.
2. The Function of the Pineal Gland and Melatonin ~ Melatonin Creates Sleep Rhythm
Now, let's discuss the "mechanism of sleep and wakefulness."
Haven't you heard phrases like "the waxing moon induces sleep" before?
In fact, it is a medical consensus that it's not the moonlight, but "14-15 hours after exposure to sunlight, a hormone is secreted that makes you sleepy."
The human brain has a pineal gland, from which the hormone "melatonin" is secreted.
This plays a significant role.
When blood levels are examined, the concentration rapidly rises around 8-10 PM, effectively regulating our internal biological clock.
In other words, it plays a role in keeping the body in an active state during the day and a resting state at night.
Also, with aging, its secretion significantly decreases.
Therefore, you can see why children can sleep soundly, but middle-aged and older adults struggle to sleep well.
3. Pineal Gland Anecdote ~ The Third Eye in Animals
Here's a related topic.
From comparative biology, it's known that other animals also have a pineal gland.
It's a crucial brain organ that secretes melatonin, the sleep hormone.
In fish, it exists in the location shown in the diagram below, and in many animals like chickens and fish, it functions as the so-called "third eye" that senses light.
In fact, the concept of the third eye is broad. 
In the fields of integrative medicine and yoga, it corresponds to the "chakra" located in the center of the forehead.
In manga and anime, Osamu Tezuka's sci-fi manga "The Three-Eyed One" and Ultraman Seven's Beam Lamp are also modeled after this.
In various academic fields, it is also referred to as the "inner eye, pineal eye" and is sometimes dealt with in mysticism and metaphysics.
4. Is the biological clock a 25-hour cycle? The role of melatonin
In one of the author's past patients, the sleep-wake rhythm was on a 25-hour cycle.
This means that their daily routine shifted by one hour each day.
If a person lives in a completely dark cave for several weeks without a clock, their daily rhythm becomes 25 hours instead of 24 hours (free run).
Since the Earth's rotation is 24 hours, the body unconsciously adjusts to 24 hours, and melatonin regulates it.
There was a time when melatonin medication wasn't available in Japan, and I had to procure it from the United States.
Currently, melatonin receptor agonists are available in Japan and can be prescribed to improve difficulty falling asleep in insomnia.
It is expected to be effective in adjusting the biological clock when evening types or shifted sleep times cannot be corrected.
The name of the drug is "Rozerem."
It has been shown to be effective in cases of reversed day-night cycles and for preventing jet lag in Olympic athletes, and methods combining it with strong light stimulation have also been introduced.
Do not self-medicate; please consult a specialist by referring to the Japan Sleep Society's "Guidelines for the Appropriate Use and Discontinuation of Hypnotics."
Regarding drug names, Rozerem comes from "rose + REM sleep" (rosy sleep), and the over-the-counter drug Doryel comes from "dream well."
Recommended Music for This Time
We introduce healing music that activates the pineal gland mentioned in the column and promotes melatonin production.
Perfect for sleep and relaxation! Please give it a try.
"Healing Music to Activate the Pineal Gland and Promote Melatonin Production"
Image Tap to listen on YouTube ♪
For listening on other services, click here ♪
[Top Specialist Profile]
Hiroshi Bando
Doctor of Medicine, Shikoku Branch Manager of the Japan Society for Integrative Medicine
Representative of the Tokushima Carbohydrate Restriction Research Group, graduated from Tokushima University, obtained ECFMG certification, and completed clinical training in family medicine in the United States. His specialties include anti-aging, carbohydrate restriction, music therapy, and sports medicine. Participated in the National Sports Festival as an ice skater (1999-2003). Chairman of the 9th Japan Music Therapy Society Conference (2009). Silver medal at the 3rd European International Piano Competition (EIPIC) in Japan (2012). Chairman of the Japan Primary Care Association Conference (2017, Takamatsu). Editor-in-Chief of four English medical journals related to diabetes (2024). Authored over 30 books, over 2,000 publications, and over 400 English papers. Representative of "Shin Rojin no Kai" (New Elders Association) Tokushima.
Official website: https://pianomed.org/
