Is there a Scientific basis for discarding “Cryonics”?

[Spearman87]

Or, if you want to go at it from the opposite perspective, can it be said to be scientifically feasible? Either way. Can anyone provide science-based opinion or evidence for why?

(I’m new here, so if I’m rehashing something that’s already been discussed <or prohihited from discussion>, please link me to the thread(s) if I'm wasting time)

I used to correspond with some people (including a physician, and a couple of science novelists who’d written books involving it) where the subject came up and who were pretty positive about it having a theoretical possibility--even if not a practical one. I have enough rudimentary knowledge (from many years ago getting a degree in biology, as well as some partially relevant graduate work) to understand fundamental ideas, problems and solutions involved. Based on things I've read I could play devils advocate to either side, but maybe there's some more decisive/useful info to be found here.

[calmblueocean]

1. zombie dogs

Here's a link I remember from last year where scientists "froze" a series of dogs by replacing their blood with a freezing saline solution. The dogs' heart and brain functions, among others, were stopped and the dogs were legally dead. 3 hours later, the saline solution is replaced with warm blood and the dogs were resuscitated.

http://news.com.com/2061-11204_3-5777094.html

I don't know how long a dog or a person could be in this frozen state and still be revived, but it seems reasonable to think that further research along these lines could extend the time one could safely stay frozen indefinitely.

[TheWraith]

2. Yes, it is practical on some level.

Many years ago some crazy Japanese scientist, I belive by the name of Hiro Suda, performed experiments where he would cryoprotect then freeze the brains of cats. Not only was he able to defrost the brains without destroying the cells, but he actually got neural activity out of them afterward.

Whether we currently have the practical technology to freeze and revive a human, without doing irreparable damage to them either physically, mentally, or neurologically, is something of an open question. It's unlikely that you'd get many people to volunteer for an experiment where there's a chance they'd end up either dead or a fresh-frozen turnip. So until somebody cures cancer and we start defrosting those people who put themselves in cold storage for that reason, we really don't know the score on that end.

[Spearman87]

3. Yes, I recall reading about the Suda experiments!

And this was WAAAAY more impressive that the “Zombie Dogs”. Suda took the brains of live cats, infused them with Glycerin as a cryprotectant, and froze them all the way down to dry ice temperature, for weeks and in one case Months on end. When thawed, they showed normal brainwave activity (But unfortunately for the poor cats, one thing Suda or anyone else had not done prior to the experiment was to perfect a means of re-implanting cat brains into healthy cats, so they were healthy brains with no place to go……)

[Spearman87]

4. Opps, I exaggerated the temperature

(It was only -20 degrees Celsius) But the period of freezing was indeed long: up to 203 days.

http://www.cryonics.org/cryobiologist.html

“The work of Lovelock and Smith was followed up by Suda and his associates (8,9,10), who made a number of critical observations on frozen glycerolized cat brains. Their first publication, in 1966, demonstrated that cat brains gradually perfused with 15% v/v glycerol at 10 C and frozen very slowly for storage for 45-203 days at the very unfavorable temperature of -20 C regained normal histology, vigorous unit activity in the cerebral cortex, hypothalamus, and cerebellar cortex, and strong if somewhat slowed EEG activity (8) after very slow thawing.”

[Spearman87]

5. Also some success at -60 degrees celsius?

"Also relevant were unpublished results mentioned in passing (9) on storage at -60 and -90 C and on the effectiveness of other cryoprotectants (dimethyl sulfoxide or polymers). Evidently, EEG activity could be obtained after freezing to -60 C and storage for weeks, but not after freezing to -90 C, and dimethyl sulfoxide was effective but not as effective as glycerol. This is confirmed in an unpublished manuscript sent to me by Suda (10), which reveals also that unit (single cell) activity can still be recorded in brains frozen to -90 C. This unpublished paper (written in Japanese) also shows that brain reperfusion was better after thawing when glycerol rather than DMSO was used."


I'm obviously doing too many things at once, to not catch that.

[Vidar]

6. Shades of Futurama (eg. Nixon's head)

[bemildred]

7. Was there ever a scientific basis for accepting it?

It is way beyond anything we can do now. So, like the lottery, it is selling hope at fairly high prices.