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Science Forum

  1. 02 Mar '11 13:54
    I am interested in cryogenics and I am trying to asses if certain essential neural information would be preserved after death and cryogenic freezing of a human brain. The particular essential neural information I am concerned here about is two kinds of info, specifically, the “neural weights” associated with each synapse and the “threshold values” associated with each neuron.
    So my questions are:

    How are the neural weights and the threshold values physically represented (in the form of chemicals or molecular/cellular machinery) when the neuron is not firing signals nor receiving signals?

    Are there some known kinds of particular chemicals/receptors/molecules the concentration of which corresponds to the threshold value of each neuron or corresponds to the neural weights of each synapse? (so you can measure the exact magnitude of each threshold value or neural weight just by measuring the concentration of the corresponding chemicals/receptors/molecules)
    And, if so, is that concentration maintained 10 minutes after death?
    And, if so, is that concentration maintained if your brain is cryogenically frozen?

    The obvious relevance of these above questions is that if such information is not physically represented after death then you would be just ripping yourself off to pay money to be cryogenically frozen since it would be logically impossible for that information to be restored in the future no matter how advance technology becomes even in a billion-billion-billion years time!!!
  2. 02 Mar '11 18:21
    I think you might want to consider experiments on animals that can be frozen. I believe certain species of frog for example survive freezing. How different are their brains, and do they forget everything?
  3. Standard member sonhouse
    Fast and Curious
    03 Mar '11 13:02
    Originally posted by twhitehead
    I think you might want to consider experiments on animals that can be frozen. I believe certain species of frog for example survive freezing. How different are their brains, and do they forget everything?
    The only problem with those kind of experiments is the brain size. It becomes a lot easier to freeze a mass of cells that can come back to life if the cell mass is small, like the brain of a mouse or frog. That would involve freezing so fast crystals don't form. There is so far no technique that can freeze humans fast enough so cell bursting crystals don't form.

    It looks like to me if such experiments were done, it would at least tell you how much information could be saved in human brains but like you said, it's a waste of time rignt now because the brain cannot at this state of the art be frozen fast enough to avoid cell damage.

    Maybe some technique could be developed to freeze the brain directly after death in such a way that no damage happens which theoretically could allow that brain to be installed in a new body later but of course you can forget that in THIS century for sure!

    I think if something like that did happen, this sojourner into the future would likely be sorely disappointed at what he would be presented with after he wakes up say in a thousand years or such. I think he would be in for a rude awakening!
  4. 03 Mar '11 17:01
    I read somewhere that oxygen deprivation just prior to 'freezing' helps to avoid damage. I put the 'freezing' in quotes because I suspect that it is really 'hibernation' that I am talking about with above freezing temperatures.
    Maybe you should look further into hibernation techniques that do not involve freezing.
  5. 03 Mar '11 18:08
    Originally posted by twhitehead
    I think you might want to consider experiments on animals that can be frozen. I believe certain species of frog for example survive freezing. How different are their brains, and do they forget everything?
    “....I believe certain species of frog for example survive freezing. ….”

    yes, you are right. And I see the implicit point -surely at least some of the neural information regarding weights and threshold values is preserved when they 'freeze' ! But, as you implied, frog brains may be just different from ours in that respect.
  6. 06 Mar '11 21:11
    frog brains may not have to learn. their functionality may come from structure, not trained experience. just guessing here.

    also, their blood may be conducive to a slow temperature drop that ends in freezing. maybe their tissues do not form destructive crystals under these conditions. in that case, maybe all humans need is the addition of antifreeze. (NOT car antifreeze!)