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29

This good non-scholarly article covers some of the usual advantages (rest/regeneration). One of the research papers they mentioned (they linked to press release) was Conservation of Sleep: Insights from Non-Mammalian Model Systems by John E. Zimmerman, Ph.D.; Trends Neurosci. 2008 July; 31(7): 371–376. Published online 2008 June 5. doi: ...


14

I found this paper by Benington and Heller that expands on the previously mentioned theory of sleep as a mechanism to renew metabolism. They hypothesise that sleep is necessary to replenish glycogen stores (mainly within astrocytes) in the brain. These stores are normally used to supplement blood glucose due to the high energy demands of the brain. It ...


7

There's an excellent, comprehensive review article on the entire process of REM sleep: Vetrivelan,R, Chang, C, Lu,J (2011). Muscle tone regulation during REM sleep: neural circuitry and clinical significance. Archives Italiennes de Biologie, 149 [DOI] [Free PDF] Projections from the sublaterodorsal nucleus (SLD) of the Pons in the brainstem are ...


7

From what I've learned, there are two theories to answer that question: Restoration - the body needs to rest in order to renew its metabolism (if an animal is active 24/7, it will constantly use up a lot energy and metabolism). It has been shown that mice that have gone a while without sleeping have a compromised immune system. Preservation - sleep is ...


6

Well, you may want to re-state your question. There are numerous multi-cellular organisms without a nervous system. So you could say that they never sleep: sponges, plants, mushrooms. This paper on the evolution of sleep concludes: A phylogenetic evaluation of sleep demonstrates that all mammals, birds, and reptiles engage in sleep, and evidence for ...


5

Polyphasic sleep can allow people to sleep at multiple regular intervals throughout the day and allows people to get by with less total sleep. I don't know of any training that can help people reduce the amount of monophasic sleep they need without a negative impact.


5

Sneezing does not occur during REM sleep, due to REM atonia.(1) Coughing on the other hand does occur during sleep, most commonly due to sickness. The following paper describes a study on the effect of honey for treating nocturnal coughing in children: http://www.ncbi.nlm.nih.gov/pubmed/22869830


5

Reading "Polyphasic Sleep: Facts and Myths (Dr Piotr Wozniak)", it is pointed out that infant humans do undergo polyphasic sleep. As this is where most of our development is obviously done, I do not know where I can further proceed with the question about how it would affect development? Perhaps the issue is more how it would effect the day to day ...


5

Our eyelids close when we sleep probably for the obvious reason that it prevents the sclera and cornea from drying out, becoming accidentally scratched (such as blowing dust) and allowing oxygen diffusion from the inside of the eyelid (to the sclera and cornea). Fragile corneas are a requirement for our vision. Thick corneas are much less fragile but then ...


5

It would be better to say that they go into an inactive, low metabolic state. This low metabolic state is often driven by the temperature in the air itself; ectothermic butterflies require outside heat-energy to become active. Basically they use this time to digest their food and produce sperm/eggs. (reference). At night, or during inclement weather, most ...


4

I'm interested in learning what influences the desire to go to bed at a particular time? What influences the getting out of bed times? It is the circadian rhythm. Circadian rhythm is mediated by the suprachiasmatic nucleus of hypothalamus, which gets afferent nerves from optic nerve. So, the circadian rhythm is mediated by light. Initiation of the ...


4

Puffy eyes are caused by fluid build up in tear ducts from extended periods of lying down. Gravity from sitting or standing slowly drains them during the day. The crusty 'sleep' that accumulates in the corner of your eyes is the residue from basal tear liquid that has seeped out of the eye and evaporated during the night.


4

The release of the hormone melatonin is responsible for the feeling of sleepiness. It is released by the pineal gland and production starts when the light fades, as it's production is inhibited by light stimulation of the retina, the onset of the production is called dim-light melatonin onset. Artificial supplementation can increase sleep quality and ...


4

Studies have proven somewhat the opposite of what you're asking For example a study from 2004 - "The impact of extended sleep on daytime alertness, vigilance, and mood" found that, Average daily POMS vigor and fatigue scores also improved during the sleep extension period And thus concluded Extended sleep leads to substantial improvements in ...


4

The enWikipedia article summarizes the best/only real research on positions that I am aware of. I read a book in high school (that is to say it was old and I have no idea what the title was) that claimed that the semi-fetal position was the best, as it supposedly maximized protection without compromising breathing too much. I can't say I've seen anything ...


4

Disclaimer: Not in any way my area of expertise. Maybe someone else can expand In relation to pregnancy, there exist one australian study (Stacey et al. 2011) that reports an increased risk of still-birth for women that sleep on their back at the later stages of pregnancy. The purported mechanism is pressure from the uterus on the inferior vena cava and ...


4

The medical term is "lagophthalmos" if the person is unable to close their eyes at night. There are several factors involved, and unless it's due to physical obstruction, lid archetecture (such as short lid length (due to surgery etc)), or facial nerve (CN VII) problems, it's not well understood. I have seen numerous people with varying degrees of this ...


3

Have you ever tried to read a complicated book after several hours of hard work that required a high concentration? Imagine that you have forced a particular area of your brain. After a hard work, the areas of the brain that we used to finish a work seem don't respond to any stimulation and make us feeling tired and as we can't understand what we are doing ...


3

The question piqued my interest, but after hunting through the literature for a bit, I hadn't found any direct answers. Then I went back and read the mouse study you cited a bit more carefully. The mouse study only made a reference to mice being affected at 4 lux, ~100x more sensitive than humans. However, for that number it cited a paper in Science that ...


3

I'm not aware of any study testing this hypothesis. I would surmise that adverse health effects are likely because the circadian clock operates on a 24-hour time frame, and because lack of sleep for ~40 hours every second day will alter hormone, cytokine and other measures to levels not normally seen in 8-hour sleep/16-hour wake cycle.


3

On the analytics of melatonin I have here a german language text by the RKI with references. Translated quote: Assay of melatonin is done by serum or sputum using RIA or ELISA. Alternatively, to infer the nightly amount of melatonin secretion it is possible to look for the melatonin catabolic metabolite 6-hydroxy melatonin sulfate (6-OHMS) in ...


3

Sleep is not homogenous - there are different phases of sleep - REM, NREM-1 to NREM-4. And these different stages may play different roles in 'rejuvenating' the body (as you put it). When you first fall asleep, you go into NREM-1 phase, which is the lightest sleep, and progresses into NREM-4, and for the first half of your sleep cycle, this cycles so you go ...


3

Since mammals all share the same neural structures it is quite likely that most non human species dream, but as yet, the simplest animal I could find that has been scientifically demonstrated to dream is the rat, as proven by Massachusetts Institute of Technology (MIT). MIT not only established that rat were capable of dreaming about the events they had ...


3

Humans have evolved for 24 hour days and our bodies would not adapt well to this short of sleep/wake cycles (whether or not they were born there, unless they have been there for many generations and have been able to evolve for the new time). Our bodies would still want to spend about the same amount of time sleeping and being awake. If we tried to adjust ...


3

These symptoms have a name: Computer vision syndrome. Basically our eyes are made to look at longer distances from 1-6 meters without much accommodation. Typically computer screens are located at a much closer distance (30-50cm), which requires constant accommodation by the eye. This leads to high stress on the muscles in the eye which subsequently get ...


2

I haven't heard of studies like the one you're proposing, but you can test this hypothesis on yourself with this app. Knowing you need to sleep less than your usual amount will probably affect the quantity and quality of your sleep, but not because of an "internal clock". Most likely, whatever you need to wake up early for will cause you some anxiety, ...


2

(too long to be a comment) You may be interested in http://en.wikipedia.org/wiki/Phase_response_curve. This graph shows how the body's circadian rhythm normally works: http://en.wikipedia.org/wiki/File:Body_Temp_Variation.png. Body temperature decreases during the night (apparently due to more melatonin production. I conjecture that the proposed schedule ...


2

I thought this was an interesting subject and I had some time to do a little search around today. I can't find anything better than the review you point out. All I can do is add a few interesting notes since 2001. Nothing really turns over Rattenborg et al. Sleep is itself a poorly understood process and most of the theories of the necessity of sleep can ...


2

Found a few samples here: http://ars.els-cdn.com/content/image/1-s2.0-S0024320503008142-gr2.gif this shows the nocturnal melatonin peak, which is apparently very important for well being


2

Balance is mediated by 3 things: the cerebellum, vision and the ear via the semicircular canal + vestibular nerve (i.e. the ear). Sleepwalkers lack the visual feedback, but they have a functional cerebellum and semicircular system which is sufficient. As for waking up and feeling disorientated, if that's when you get up fast that's because your ...



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