Monday, April 4, 2016

C for cerebrospinal fluid (A to Z challenge)

Yesterday I mentioned importance of sleep and today I would like to talk a little more about brain 'self-cleaning' miracle.

The brain produces about 2 cups of cerebrospinal fluid (CBF) per day and that fluid is constantly reabsorbed during the day leaving about quarter of a cup at any one time. It acts like a cushion for our brain during the day and at night the miracle happens...  In the deep-sleep mode the brain turns on the cleaning cycle, much like a dishwasher.

When awake, neurons fire constantly to keep the brain alert, causing the brain cells to expand to about 86% of the volume of the brain. During deep sleep brain's cells shrink, leaving more space for the brain and spinal cord's fluid to move and pickup toxic waste. A sleep-deprived brain has reduced efficiency in garbage removal. And as we get older we sleep more lightly, getting less of deep sleep and as a result we are having more often those 'senior's moments' (that's my own very personal opinion).

Now,  just in a few words about our sleep stages:

Stage 1 (5-10% of total sleep in adults) - Your eyes are closed, but it's easy to wake you up. 

Stage 2 (45-55% of total sleep in adults) - You are in light sleep. Your heart rate slows down and your body temperature drops. The body is getting ready for deep sleep.

Stage 3 (15-25% of total sleep in adults) - This is the deep sleep stage. It's harder to rouse you during this stage, and if someone woke you up, you would feel disoriented for a few minutes. During the deep stages of sleep, the body repairs and regrows tissues, builds bone and muscle, and strengthens the immune system. (The brain shrinks and turns the cleaning cycle).

Human sleep occurs in periods of 90 minutes on average and usually we have four or five cycles per night. There is a stage after deep sleep when we are returning to stage 1. It's called REM (rapid eye movement) and takes 20-25% of total sleep in adults. During this stage most muscles are paralyzed, and heart rate, breathing and body temperature become unregulated, the sleeper may experience vivid dreams. The function of REM sleep is uncertain but a lack of it impairs the ability to learn complex tasks. Functional paralysis from muscular weakness in REM may be necessary to protect organisms from self-damage through physically acting out scenes from the often-vivid dreams that occur during this stage.

Stay tuned, tomorrow  I will talk about brain food.


  1. I found this very interesting.
    I have recently changed my diet and this has changed my sleep pattern. I now sleep through the night and wake up later. I wonder if diet affects the quality of the fluid you wrote about here. I am guessing that cerebrospinal fluid and Alzheimer's are linked somehow.
    Thank you again. You have given me something worthwhile to consider.

    1. Yes, the cerebrospinal fluid is linked to prevention of Alzheimer's. Since brain goes through the 'cleaning cycle' during our deep sleep, beta-amyloid (a protein associated with Alzheimer’s) is slowly removed.

      I'm not sure about diet effect on a sleep pattern but certainly by changing our eating routine can help to have a good night sleep. Having the last meal of the day light and early (at least two hours before bedtime) will help us to sleep better. Tomorrow I will discuss diet so stay tuned. I'm sure I will like to read your story.

  2. I have been reading your posts and I find them very interesting. I think most of us do not understand Alzheimer's and are scared to find out about it. Thank you for educating us with what you know and I look forward to learning more as the days go on!

  3. Very interesting! Thanks for the explanation of the CBF cycle. My 99-yr-old grandmother has Alzheimer's, and so your posts hit close to home.

  4. Wow! I learned a lot in just a few minutes. Can't wait for tomorrow.

  5. Evalina, this is most interesting and informative. Thank you.

  6. Thank you Evalina... I'm overdoing and not sleeping enough. Appreciate the reminder. This is my last visit and I'm off to bed. Tomorrow, do it all again.

  7. Very interesting article. I am a light sleeper...I wonder if I go into deep sleep every night.

    Visiting from A to Z Challenge
    Pam's Unconventional Alliance Team
    A Whimsical Medley
    Twinkle Eyed Traveller

  8. Interesting information. Due to menopause I've been having great difficulty falling asleep...

  9. Thank you again.. I will never feel guilty about sleeping again.

  10. Interesting stuff. Thanks for sharing.

  11. This was a fascinating post - it's turning into a great series - thank you :)
    A Stormy’s Sidekick
    Special Teaching at Pempi’s Palace

  12. Very interesting. Fortunately we are all pretty good sleepers in our house. Some of my friends seem to have nocturnal children!

  13. Great post and very informative!


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