Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

What happens during sleep that makes it necessecary?

  1. Feb 17, 2004 #1
    Off the top of my head, the only things I can think of that would make sleep necessary is building up reserves of ATP and using energy towards rebuilding tissue that wouldn't be available during the day. But it seems that there has to be more, otherwise you could just eat alot of carbohydrates and never have to sleep...
  2. jcsd
  3. Feb 19, 2004 #2
    Sleep is also really important for the brain.I haven't done alot of research about this but it is evident that critical neurological things are going on that are necessary to remaining mentally healthy. They did alot of sleep deprivation studies in the 1960s and discovered that after about four days with no sleep people became psychotic. A return to normal amounts of sleep reversed this.
    Alot of mentally ill people, especially people prone to manic episodes, tend to start down the road to their next mania or psychotic episode by going through a period where they lose alot of sleep.
  4. Feb 19, 2004 #3
    I've read that sleep deprivation, particularly lack of REM sleep (which usually comprises the last 90 minutes, or so, of sleep (IIRC)), can lead to symptoms exactly like those of drinking too much alcohol.
  5. Feb 19, 2004 #4


    User Avatar
    Science Advisor

    I read somewhere that sleep is when the body converts adneosine back into ATP. If that is correct, then no amount of carbing up would help, because the energy in the carbs you eat would not be converted to a usable form.

    Also, sleep is the only time the body produces seratonin, without which the brain shorts out.
  6. Feb 20, 2004 #5
    Do you mean adenosine diphosphate (ADP) back to Adenosine Triphosphate (ATP)?

    If thats the case, i don't believe it is true. Your cells must continuously replenish ATP via glycolysis (or other means) or it would probably die in a second.

    some more information - http://www.sagewoodwellness.com/Doc0002.htm [Broken]

    Perhaps sleep evolved to conserve energy during the night, and now is used for other purposes, some say its necessary for the brain to process the days events, others say it is to repair tissue in a relaxed state.. its probably all of these.
    Last edited by a moderator: May 1, 2017
  7. Feb 21, 2004 #6
    I have sometimes wondered whether there might be a link to gene expression in the neurons, with there being a conflict between the chromosome state required for waking neural activity, and for gene expression.

    There is a published paper about a woman in Japan who sleeps for 20 odd days, then wakes for 20 odd days. I assume that when she is sleeping she is woken for meals, and then drops back off to sleep. The only thing that they could find wrong was that her DNA did not pack properly into the highly condensed Heterochromatin state. This syndrome is normal fatal, but not in her case.
  8. Feb 21, 2004 #7


    User Avatar
    Science Advisor

    No, I 'm talking about adenosine, once all phosphates have been stripped off. The resulting molecule, adenosine, has been at least tentatively linked to the urge to sleep. Some tranquilisera work because they mimc adenosine and fit adenosine receptors. Caffein keeps us awake because it blocks these same receptors.

    After some searching, I found http://web.sfn.org/content/Publications/BrainBriefings/adenosine.html [Broken] which refers to the same study where I first saw that information.
    Last edited by a moderator: May 1, 2017
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook