when neurons start shouting “go to bed NOW!”

DrosophilaA study carried out in fruit flies (2–4 millimetres long Drosophila) by some clever researchers at Oxford University’s Centre for Neural Circuits and Behaviour (CNCB) has recently pointed out a sleep mechanism which is meant to be relevant to humans.

Human sleep regulation is supposed to be managed by two mechanisms:

  • a first one, called body clock, related to the external environment. For instance, thanks to it, humans and others animals get used to the 24-hour day-night cycle and regularly alternate sleep-wake cycles;
  • a second one, related to the body homeostasis, which monitors the internal environment and basically makes us feel spleepy when we’ve been awake for too long. Such mechanism works like a sleep switch and is separate from external factors.

i-am-not-sleepy-and-i-will-not-go-to-bedProfessor Gero Miesenböck, in whose laboratory the research was performed, says that “what makes us go to sleep at night is probably a combination of the two mechanisms. The body clock says it’s the right time, and the sleep switch has built up pressure during a long waking day“. Now, the researchers found (in the tiny Drosophilae’s brains) a group of sleep-promoting neurons that work as a thermostat which automatically turns on when it’s too cold: such neurons are active when the body is tired and needs to sleep, while they don’t fire under fully rested conditions. Doctor Jeffrey Donlea, specialised in testing new scientific ideas in flies at the CNCB, says that “there is a similar group of neurons in a region of the human brain. These neurons are also electrically active during sleep and, like the flies’ cells, are the targets of general anesthetics that put us to sleep“. Therefore, a similar molecular mechanism is likely to operate in humans too. In order to specifically solicit the sleep switch, certain genes were silenced in a group of flies’ brains: a key molecular component was disabled in order to keep the sleep-inducing neurons permanently switched off. The mutant flies were found not to be able to catch up on lost sleep after being kept awake all night. Such behaviour was assumed to be caused by the disabled molecular component, thus identified as a cause of sleep disorder.

Upon further investigation, this study might help the identification of new targets to improve treatments for sleep disorders like insomnia. In the long term, this research work may provide precious hints to find the answer to the big question: “What is the purpose of sleep?“. For the moment, what is sure is that the greatest enemy of sleep is the Internet.


main sources: this and that

all you need is MgCl2

In modern times like these, what does the 99% of people lack? Shut up, you naughty readers… the right answer is Magnesium Chloride 😉

mgcl2Magnesium chloride, Wikipedia‘s words, “is the name for the chemical compounds with the formulas MgCl2 and its various hydrates MgCl2(H2O)x“. Highly water-soluble, it is usually extracted from brine, sea water and (via solution mining) out of ancient seabeds. Because of many factors (intensive farming techniques, food processing and refining, massive use of preservatives), the food we usually eat is deficient in magnesium, whose daily requirement is about 420/320 mg for the average adult man/woman. This website (in french) says that a diet without MgCl2 “is incompatible with life“… besides the slightly apocalyptic atmosphere that we might suddenly feel, magnesium is actually depicted as a truly essential mineral for human nutrition. “Magnesium is needed for more than 300 biochemical reactions in the body“, says this other website… my dumb reaction to all these facts: ok, I didn’t know about that, but if it’s so important, why am I still alive? 😀

magnesium-chlorideNo, we’re not supposed to schedule an appointment with The Lord (each of us with their own one, of course..!), but it’s good to know that our body likes to point out deficiency in magnesium by means of the following main alarm symptoms: chronic fatigue and lack of energy, insomnia, confused and uncontrolled emotional reactions, rapid pulse and muscle spasms, nervousness and irritability, and so on. For sure it’s not a big deal, it’s something that, more or less, we experience from now to then… what has been scientifically proven is that reestablishing the correct magnesium body requirement has very positive healing effects on anxiety, muscular pains, asthenia (when, in the morning, you wake up and you already feel dead tired), blood and body infections, nervous and emotional well-being, digestion and a lot more things that colour our daily life 🙂

sachetIf you’re curious (I was), just go to the closest chemist’s/pharmacy/grocery store and ask for magnesium chloride. They’ll sell you a cheap 20 g sachet to be dissolved in 1 litre of water. It tastes pretty bad actually, very bitter (if cooled down in the fridge, it will be less unpleasant), but it’s totally tolerable since you’ll have 20 days to empty this magic bottle (and not half a day, as I thought. Do not try that, DO NOT!)

power napping !

siestaI’ve always loved spanish people for their siesta culture… Wikipedia defines the siesta as a short nap taken in the early afternoon, often after the midday meal and explains that the word origin is “hora sexta”, meaning “sixth hour” (after the dawn, so about midday) in ancient latin language. Anyway, I’ve decided to stop yawning for a while and learn some interesting things related to naps 🙂

sleep-deprivedThe first important thing to know is that the sleep need varies by age and condition. The sleep need, trivially, is the amount of sleep that a person needs to properly “recharge batteries” and wake up again without feeling tired. On average, newborns need 12 to 18 hours of sleep per day, adolescents about 9 hours and adults 7 to 9 hours per day. First consideration: Yes, we would all like to be newborns for the rest of our lives! Second consideration: the sleep need decreases with age and enormously varies among individuals, so there is no rule. What is sure is that sleep is cumulative: if at night we don’t sleep enough, the next day we’ll be fatigued and actually feel a sort of “sleep debt”.

Many hypotheses have been made to explain the functions of sleep, but it is still too hard to draw up an exhaustive list endorsed by scientific evidences. The second important thing to know is that our sleep follows some patterns known as sleep cycles. Without giving too many details (that you can find here), we sleep by cyclically alternating light and deep sleep phases. Intuitively, it is much easier to wake up during a light sleep period, better known as REM sleep phase, than during a deep sleep one. As it is depicted by the figure below, under normal conditions REM sleep phases recur on average every 90 minutes.


When we decide to take a nap, we should know that, if we are about to start the usual sleep cycle, after about 45 minutes we’ll be in the midst of the first deep sleep phase. In a sense, if we need to set the alarm, we should decide for either taking a short nap (20 to 30 minutes) or a long one (90 minutes), so as to wake up immediately after or before a light sleep phase. Unless you’re lucky enough to afford a nap of one hour and a half per day, you should probably take these considerations seriously 🙂

how-caffeine-2-360x240As this website explains, a power nap is a sleep session that happens during the day (ideally between 1:00 to 4:00 PM) lasting between 10 and 30 minutes. Power napping has been scientifically assessed as an effective way to relax, reduce fatigue, boost responsiveness and improve the mood. Apparently, a quick nap is even better than caffeine to improve both motor and learning skills.

Of course, napping can have negative effects as well. This webpage reports that “napping isn’t for everyone. Some people have trouble sleeping in places other than their own beds, while others simply can’t sleep during the day. Right after the nap time, it may happen to feel disoriented and groggy… this is called sleep inertia. In other cases, a nap could interfere with night-time sleep and make us feel perfectly awake at 2:00 AM, thus leading to wonderful insomnia night sessions (that I wouldn’t wish even on my worst enemy).

Kind Yawns to You all.