[ExI] Another step towards uploading

Max More max at maxmore.com
Mon Oct 7 21:34:25 UTC 2013

Someone mentioned a Cryonics magazine article on plastic embedding vs
cryopreservation. You can find the article here:



On Mon, Oct 7, 2013 at 12:42 PM, Anders Sandberg <anders at aleph.se> wrote:

>  On 07/10/2013 15:45, John Clark wrote:
> On Mon, Oct 7, 2013 at 1:43 AM, Eugen Leitl <eugen at leitl.org> wrote:
> > Perfusion by diffusion works only on cm^3 scale systems.
>  OK, but how is that a problem? Just cut the big brain up into slices one
> centimeter thick or less; the gap between the slices could be made very
> thin indeed, on the order of 30 nanometers.
> The problem is: how do you cut a brain? A fresh brain has the consistency
> of stringy toothpaste: any cutting will do massive damage. Methods for
> sectioning brains properly always start with putting them in a bucket of
> formaline... for two weeks or more: http://goo.gl/9ueYjN
> Think about what happens during that time. Yuck. As this paper shows,
> diffusion is slow enough to produce noticeable gradients of immunostains:
> https://www.sciencedirect.com/science/article/pii/S0165027087800018
> Now, there seem to exist perfusion based methods, and fixing in situ seems
> to be a great start for getting something that can be sliced well later:
> http://www.ncbi.nlm.nih.gov/pubmed/9372749
> http://www.abcam.com/ps/pdf/protocols/perfusion.pdf
> Some aim at rapid fixation by injecting fixation liquid through basal
> blood vessels and the ventricles, followed by the bucket for a few days:
> http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1860363/
> It might even be applicable to whale brains (!):
> https://www.sciencedirect.com/science/article/pii/S0165027002001826
> "Due to limited space and supplies of fresh water on board, the fixative
> usually had to be mixed for each whale using seawater instead of fresh
> water. When seawater was used, NaCl was not added to the solution. To
> prepare and open the skull, sharp painter scrapes, a circular bone saw with
> an adjustable blade, chisels and hammers were needed. The use of chemicals
> and saw on a very unstable working platform and the risk of spatters of
> bone splints, necessitated that the operator wore protective glasses,
> gasmask, chemical resistant industrial gloves, heavy oilskins and strong
> boots." - ah, tough Norwegian science!
> --
> Anders Sandberg,
> Future of Humanity Institute
> Oxford Martin School
> Faculty of Philosophy
> Oxford University
> _______________________________________________
> extropy-chat mailing list
> extropy-chat at lists.extropy.org
> http://lists.extropy.org/mailman/listinfo.cgi/extropy-chat

Max More, PhD
Strategic Philosopher
Co-editor, *The Transhumanist Reader*
President & CEO, Alcor Life Extension Foundation
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.extropy.org/pipermail/extropy-chat/attachments/20131007/81b5b781/attachment.html>

More information about the extropy-chat mailing list