Chemical Brain Preservation

[John Clark]

On Sat, Mar 21, 2026 at 3:06 PM Keith Henson via extropy-chat <extrop...@lists.extropy.org> wrote:

> This issue I have muddled by proposing being able to move to and from
the uploaded state.  If you can do this, continuous memory across both
states, it is hard to deny that a person exists in the uploaded state.

Keith, I'd be interested in hearing your thoughts on Alcor offering chemical brain preservation, at least as an option, given that it would almost certainly preserve information better than current methods. 

John K Clark

[Keith Henson]

That's a lot of topic drift.

I simply don't know if chemical preservation would be better or not.
It probably would if brains could not be kept in LN2, but in an
institutional failure of that magnitude, I am not sure it would make
much difference.

We know that cryoprotected tissue can be revived from LN2, the same is
not true for chemical fixation. making LN2 the conservative approach.
Whether that carries over to brain information is likely but not
certain.

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.

Keith
>
> John K Clark
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[John Clark]

On Sun, Mar 22, 2026 at 2:25 PM Keith Henson <hkeith...@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. "

John K Clark