[ExI] [Extropolis] Chemical Brain Preservation

[John Clark]

On Sun, Mar 22, 2026 at 2:25 PM Keith Henson <hkeithhenson at gmail.com> wrote:

> I simply don't know if chemical preservation would be better or not.
>

*Electron microscopic photographs of brains that used glutaraldehyde
fixation and then cooled to liquid nitrogen temperatures for cryogenic
storage displayed far more detail than brains infused with Alcor's current
cryoprotectant and then frozen. *


> * > It probably would if brains could not be kept in LN2,*


*I don't think there's any "probably" about it. Ideally you'd want both
chemical fixation and liquid nitrogen temperatures, but with chemical
fixation if due to some malfunction the brain warmed up it might not be the
total catastrophe it would be as it would be with current methods. I wrote
to Eric Drexler some years ago about this and he agreed with me, I wasn't
surprised because he mentioned something very much like it in his book
"Engines Of Creation". *

>
* > We know that cryoprotected tissue can be revived from LN2, the same
> is not true for chemical fixation.*


*Yes but that's not important. If I am ever revived I think there is zero
probability I will have a chemical brain like I do now.  *


> *> making LN2 the conservative approach.Whether that carries over to brain
> information is likely but not certain.*


*Nothing about this is certain but we can play the odds, so I'd put my
money on the procedure that produces the clearest electron microscopic
pictures of brain slices, or I would if Alcor would just offer it.    *

>
* > My thoughts on getting to the upload era are like Woody Allan's.
> If that does not work, Alcor is the best you can do.*
>

 *Speaking of Woody Allen , I wrote the following back in 2018, I think
it's still valid: *

*"Woody Allen said "I don't want to achieve immortality through my work; I
want to achieve immortality through not dying. I don't want to live on in
the hearts of my countrymen; I want to live on in my apartment”, well maybe
there is a way. Yesterday the Large Mammal Brain Preservation Prize was
awarded to 21st Century Medicine and lead company researcher Robert
McIntyre. They used both glutaraldehyde fixation and cryogenic storage, and
proved that a pig's brain connectome, that is the 150 trillion synaptic
connections that are thought to encode memory and the whole mind, is
preserved. *

*And because it is stored at liquid nitrogen temperatures it could be
preserved for centuries. 3D pictures were made by an electron microscope
after the brain was rewarmed and they showed amazing preservation, and
there is no reason to think molecular-level information wouldn't be
preserved too. It's even more impressive when you consider that the
pictures were made after rewarming because most of the damage happens at
that stage, I would have been delighted even if the pictures were made
while the brain was still frozen, but this is even better. Kenneth Hayworth
a PhD in Neuroscience said:*

*"Let that sink in…  Aldehyde-stabilized cryopreservation, if properly
applied TODAY, could preserve the information content of a human brain for
indefinitely-long storage."*

*At this point there is little doubt, Aldehyde-stabilized cryopreservation
works and it does a much better job than the method Alcor currently uses.
And at this point no new science is required, we just need improved
technical procedures to make it practical to use in a hospital setting and
the will to do so.*

*There is more about this here:*

*https://turingchurch.net/cryonics-for-uploaders-the-brain-preservation-prize-has-been-won-cebbe98c241a*
<https://turingchurch.net/cryonics-for-uploaders-the-brain-preservation-prize-has-been-won-cebbe98c241a>.
"


*John K Clark*






>
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