Sleep Cycle May Originate in Ancient Oceans

What do we humans have in common with ocean plankton – specifically  the marine ragworm, Platynereis dumerilii? Melatonin.

Creative Commons (CC BY-NC-SA 3.0) © Natural History Museum, London

Creative Commons (CC BY-NC-SA 3.0)
© Natural History Museum, London

Scientists at the European Molecular Biology Laboratory recently discovered that melatonin, the hormone that regulates our sleep and waking cycles, also regulates the rising and falling of Platynereis larvae. (1)

The Platynereis dumerilii are centipede-like worms that produce larvae that float through the ocean waters as zooplankton. Every night they sink down into deep water, only to rise back up with the help of little hair-like flippers called cilia by day, reaching the surface at dusk.

Every night, an increase in melatonin levels in this larva's brain makes it move away from the sea's surface. EMBL/M.A.Tosches

Every night, an increase in melatonin levels in this larva’s brain makes it move away from the sea’s surface. Credit: EMBL/M.A.Tosches

Scientists have wondered what prompts these larvae to make their vertical migrations. Now they know. Platynereis dumerilii have melatonin in their tiny brains. When the larvae are exposed to light, light-sensitive neurons secrete melatonin, prompting the cilia close up and the larvae sink; when secretion stops in the darkest depths of the ocean, the cilia open up and begin flapping, lifting the tiny larvae to the surface of the water.

In human beings, melatonin levels generally rise at dusk, helping us to fall asleep, and decline at dawn, prompting us to wake up. That’s why melatonin has been called the “dracula hormone:” it comes out under the cloak of darkness.

Neurons sense light and produce melatonin, driving this larva’s nightly migration. Credit: EMBL/M.A.Tosches

Neurons sense light and produce melatonin, driving this larva’s nightly migration. Credit: EMBL/M.A.Tosches

Human beings and ocean plankton (and most every other creature on earth, for that matter) have neurons that sense the presence and absence of light which guide cycles of expansion and contraction, sleeping and waking. Platynereis dumerilii actually have eye-like structures called “eye spots.” (2)

“Life evolved in the ocean,” observed Maria Tosches, but unfortunately we cannot go back 600 million years and watch what happened. But studying marine ecology and neurobiology can still tell us something about where our brains come from.”

1) Tosches, M.A., Bucher, D., Vopalensky, P. & Arendt, D. Melatonin signaling controls circadian swimming behavior in marine zooplankton. Published online in Cell on 25 September 2014.

2) Platynereis dumerilii, Natural History Museum,

The Connection Between Sleep and Weight Gain

Jeff Mann (over at Sleep Junkies) has put together a great info-graphic summarizing recent research on how poor sleep promotes weight gain. It’s a multifaceted relationship that is both physiological and psychological, and he has kindly made it available for re-posting.

(Unfortunately, I can’t make the graphic smaller, so there’s overlap on my site. You can view a clearer version of it at:

Sleep and obesity infographic
Courtesy of: Sleep Junkies

“Late Nights and Appetites”

Courtesy of: Sleep Junkies


Free, Do-It-Yourself, Remedies for Sleep

imgresSleeping pills are among the most advertised, prescribed and profitable medications available. Last week, a market research group revealed that $54.9 billion were spent on sleep aids worldwide in 2013, and predicted the figure would rise to $55.8 billion this year . (1)

The figures continue to rise despite the fact that the use of sleeping pills has been found to increase the risk of death, and “could be as risky as smoking cigarettes,” according to one study author, Dr. Daniel F. Kripke. (2)

It’s time (past time, actually) to look for some alternatives. Since I prefer things I can do myself for free, I’d like to highlight two sleep-inducing, evidence-based approaches you can take at home: shiatsu massage and yoga.

Researchers teach patients hand massage

Researchers teach patients hand massage

This week researchers at the University of Alberta published a paper on a pilot study they conducted in which they taught 9 patients with serious, chronic, sleep-interrupting pain to give themselves hand shiatsu massages before bed. The results were promising: patients were able to fall asleep faster, and stayed asleep longer. Nancy Cheyne, who often lay awake most of the night due to back pain, reported: “Usually within a few minutes of doing the pressure treatments, I’m gone – asleep. Sometimes I can’t even finish. I just go out.” (3)

I was unable to find out which points were used in the shiatsu study, but there are some good youtubes by shiatsu practitioners demonstrating common approaches to reducing anxiety and promoting sleep. My favorite was this one from the folks at Bay Area Natural Health. (4)

Researchers were unsure as to what enabled the patients to sleep better. It could have been the shiatsu points themselves, or it might have been the simple fact that patients had to pay attention to something besides their pain when they were readying for sleep. Anxiety, and the thoughts that attend it, commonly keeps sleep at bay.

Napoleon reportedly taught himself to still his mind before bed by imagining that each thought was a drawer in an enormous cabinet and  shutting one after another until he fell asleep. A elderly man once told me he counts back from 100 in order to fall asleep. Same idea.

Yoga has also been shown to improve sleep. Researchers at Harvard Medical School taught 20 insomniacs a series of basic yoga poses and asked them to practice daily for 8 weeks. They fell asleep sooner, and slept longer. Two 75-minutes yoga sessions a week were shown to improve sleep (and reduce symptoms) in cancer survivors. (5)

So next time you can’t fall asleep, or wake in the night, try doing the child’s pose (at right), or pressing that point at the crease of your wrist (above), or simply shutting the drawers on all your thoughts.

(1) BBC Research, Sleep Aids: Technologies and Global Markets, June 2014,

(2) WebMD, Sleeping Pills Called as Risky as Cigarettes, February 27, 2012,

(3) Science Daily, Hand Shiatsu Treatment Explored as Sleep Aid, June 17, 2014,


(5) Michael J. Breus, Yoga Can Help with Insomnia, October 4, 2012,

Sleeping Outdoors

imgresNow that school is out, the days are long (for those of us living in the northern hemisphere), and summer’s heat is kicking in, it’s a perfect time to sleep outdoors. Whether you are camping in the back yard or in a national park, sleeping on the porch or the roof, or taking a nap on the beach or swinging in a hammock under a tree, outdoor sleep exposes us to the natural cycles of light and dark that tune our body clocks.

120px-Eye_scheme_mulitlingual.svgThat’s because our eyes serve two purposes: to see what’s around us, and to identify the degree of light, which prompts hormonal changes that regulate many bodily functions, including hunger and sleep. (1) When we live indoors with artificial light, we delay the release of melatonin, the hormone that makes us sleepy, and often stay up late.  When we wake in the morning, melatonin levels tend to remain high, leaving us feeling groggy for some time.

(If you struggle with what the scientists call “sleep inertia” – the desire to stay asleep no matter how late it is – get outside as early as you can (or turn on the brightest lights in the kitchen), so your eyes can tell your brain to reduce melatonin and wake up. Turning down the lights after dark and avoiding LED screens will also help avoid sleep inertia)

imgresBack to sleeping outdoors. Researchers at the University of Colorado sent 8 volunteers out camping for a week without any artificial light to see what would happen to their sleep cycles. By the end of the week, they were all falling asleep and waking up around the same time, despite having vastly different sleep patterns before camping. The researchers tested their hormone levels and discovered that their bodies released melatonin at sunset and stopped releasing it at sunrise, making it much easier to get up in the morning. (2)

imagesThere was a time when people were encouraged to rest outdoors to improve their health. In the early years of the 20th century, when tuberculosis was rampant, people began building sleeping porches onto their houses, and hospitals rolled patients onto screened porches for fresh air. (3)

To this day, parents and day care centers throughout Scandinavia put children outside to nap – even in the winter – in the understanding that fresh air increases their resistance to coughs and colds. They also claim that the tots sleep longer outside. (4)_66004274_sleepingbabies_624

Mahatma Gandhi was a great fan of sleeping outside. He considered it to be one of the essential “keys to health,” as long as you can keep yourself warm and dry. He wrote that the “ever-changing beautiful panorama of the heavens” is soothing, making for a “peaceful, refreshing sleep.” (5)

In recent years, people around the world have been organizing “sleep outs” to raise money for refugees and homeless people who have no choice but to sleep outside. My favorite is the Souixland Sleep Out. As one member explained: “That’s when we’re getting together to freeze our collective tuckuses off,” adding: “Did you know that there were around 2,500 homeless people in Sioux City last year – about 200-250 on the streets on any given day?” (6)banner-u93

(1) Ignacio Provencio, “Hidden Organ in Our Eyes Found to Control Circadian Rhythms and Emotions,” Scientific American, May 2011,

(2) Michelle Castillo, “Camping May Help Reset Your Internal Clock, CBS News, August 2, 2013

(3) Charlie Hailey, “From Sleeping Porch to Sleeping Machine: Inverting Traditions of Fresh Air in North America,” Traditional Settlements and Dwellings Review, Volume XX, Number 11, 2009,

(4) Helena Lee, “The Babies Who Nap in Sub-Zero Temperatures,” BBC News, February 21, 2013,

(5) Mahatma Gandhi, Key to Health (Ahmedabad, India: Navajivan Publishing House, 1948)

(6) “Siouxland Sleep Out: Getting Out There for the Homeless,

Taking Back Sleep in the City

New York City by Night (Wikimedia Commons)

New York City by Night (Wikimedia Commons)

It used to be that New York City alone claimed the title of “The City That Never Sleeps.” Then Berlin, Hong Kong and London joined in, followed by Buenos Aires, Sao Paulo, Tel Aviv, Mumbai, Cairo, Madrid, Barcelona and Belgrade. Now, most every urban center in the world can lay claim to the title, with active night lives and round-the-clock noise and light that can make sleep difficult at best.

WNYC's Clock Your Sleep Logo (WNYC website)

WNYC’s Clock Your Sleep Logo (WNYC website)

Some cities are taking sleep back into their own hands. In New York, WNYC Radio has initiated a city-wide sleep project, encouraging residents to track and report their sleep online, and identify what keeps them awake. The idea, explained WNYC’s Brian Lehrer, is to learn “how New York sleeps and how we might sleep better.” (1) With over 3,000 people reporting to date, they’ve already learned that residents of the Big Apple tend to hit the hay  an hour later than the rest of the country, but end up getting the same amount of sleep. (2)

Mayor Bill de Blasio, an admitted night owl, said in November 2013: “I think we should re-orient our society to stay up late. But I don’t think that’s happening right now.” (2)

Bad Kissingen (Google Public Domain)

Bad Kissingen (Google Public Domain)

Seven time zones east of New York, there’s a small spa town in Germany, Bad Kissingen, that has taken up the challenge to become sleep-friendly. The mayor and town council agreed to gather data about when residents prefer to sleep with hopes of adjusting school, hospital and clinic schedules and lighting accordingly.

Dr. Thomas Kantermann, the project supervisor, explained: “My great aim for this town is to make Bad Kissingen the first town in Germany… where your internal time is acknowledged.” (3)

Imagine that! Some say he’s dreaming, but I think they’re just envious.

(1) Clock Your Sleep: Young Kids and Parents,

(2) Six Facts That Will Change the Way You Think About Sleep in New York,

(3) The Town That’s Building Life Around Sleep

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