It intrigues me that scientists are no closer to understanding the main biological function of sleep than they were hundreds of years ago. Surely something so important to our health and wellbeing would be known inside and out by now? Apparently not. It is still as great a mystery as ever.

Already a member? Login

312,086 Members and growing Join Now for FREE

Why Join Blackmores?

Discover all of the features available to members only, including interactive tools, community participation and a free welcome gift.

Watch a quick video Watch a quick video

Members Wellbeing Goals

What do you want to achieve? Motivate yourself and others to better health.

less carbs, less grains rebecca, SA

Be healthier Nardine, WA

Loose weight, age healthy. Sue, NSW

2 FINALLY reach my first 'stepping stone' goal Heidi, QLD

Lose weight and have more energy Debbie, NSW

Set your goal Prev | Next

Hot topics

Blackmores Community Forum

Join health discussions, share experiences and get wellbeing tips and advice. Start a discussion now.

View all

Print

Why do we need to sleep?

Was this helpful?
  • Add to bookmarks
  • RSS
Why do we need to sleep?Why do we need to sleep?

It intrigues me that scientists are no closer to understanding the main biological function of sleep than they were hundreds of years ago. Surely something so important to our health and wellbeing would be known inside and out by now? Apparently not. It is still as great a mystery as ever.

Whilst doing my usual trawl through databases to find interesting research for our blog readers, I came across an article on a new hypothesis for why we sleep; to refuel energy stores in our brains. Well that makes sense, doesn’t it? I certainly know how my brain operates without enough sleep. The article claims that contrary to popular belief, sleep is not about resting the body. Consensus now is that sleep mostly does something for the brain.

Over a decade of research has given us details about what happens during sleep, but not a lot of information as to why. REM (rapid eye movement) sleep is the active phase during which we dream, but we spend about 80% of our time in non-REM sleep, where our EEG (electroencephalogram) readings produce a higher amplitude and lower frequency result. (Interestingly echidnas do not go into REM sleep, as opposed to most other mammals that have about as much time in it as we do.)

Apparently, there are more theories out there about sleep than could possibly be correct, and there is evidence for and against most of them. However, prominent researchers, Bennington and Hellar, from Stamford University put forward a compelling case that the main function of sleep is to restore glycogen levels in the brain (glycogen is a storage form of glucose). They propose that when the brain starts to feel its energy reserves depleting, it produces a substance called adenosine. Interestingly caffeine and theophylline (a substance in tea) inhibit adenosine receptors. The pieces are starting to fit together.

How might adenosine work? Hellar hypothesises that when enough adenosine molecules bind to receptors in the brain, it causes the neurons (brain cells) to fire in synchronicity and at a slower rate which results in non-REM sleep. He likens it to a choir singing the same song, as opposed to being awake, where neurotransmitters such as serotonin and norepinephrine keep the neurons constantly firing in what he calls ‘static sounds and discordant voices.’ Further research is needed, but if their theory proves to be correct, it will be an interesting breakthrough in our scientific understanding of sleep.

References available upon request

Comment

Male Female

I have read and agree to Blackmores Terms of use


* Your post may appear online after a member of the Blackmores Online Team has reviewed it.

Comments

Charmaine Charmaine

Hi Carl,
Adenosine has a number of roles within the body – and due to the way adenosine works in the body (and the different receptors that it binds to) some of these roles can seem contradictory.
Adenosine plays a role in cellular energy and the metabolism of energy in cells through its role as a component of ATP (however - this role in cellular energy is very different to the increase in physical energy that you would feel for example after taking a stimulant).
Even though adenosine has this role in cellular energy it acts as an inhibitory neurotransmitter in the central nervous system – reducing the excitability of neurons in the brain, which contributes to its role in promoting sleep, and suppressing arousal.
As to the interaction between adenosine and caffeine – caffeine’s stimulatory effects on the body are primarily due to its ability to block adenosine binding to its receptors – which means there is less of the normal inhibitory action of adenosine – resulting in a stimulated nervous system.
I hope that helps Carl!
Regards, Charmaine (Blackmores naturopath) Charmaine, posted 30+ days ago. Report Abuse

Doesn't adenosine increase your energy levels? So how can caffeine inhibit adensonine receptors, when caffeine is a stimulant?

Source: http://www.b2bworld.com.au/hp/category99_1.htm

Carl , posted 30+ days ago. Report Abuse

Notification

Your post is pending approval

Your post has been sent to a Blackmores Administrator for approval as it contains words or phrases that may not comply with our Posting Guidelines and Terms of Service. A Blackmores Administrator will review your post to determine whether or not it can be published.

You will be notified via email when your post is published or if it has been declined.

For further information about what can and can't be discussed within the Blackmores Community, please view our Terms of Service and Posting Guidelines.

X
  • Add to bookmarks
  • RSS
Default tooltip content in here
Del.ic.ious Facebook MySpace Digg Twitter