Freeze Recovery Drug - Step Toward Suspended Animation? 110
arete writes "Apparently a simple injection (in rats and mice so far) can revive body functions before warming. Since you're cold, your brain isn't using oxygen, and doesn't go into oxygen deprivation. But it lets breathing and autonomic functions (like shivering) restart even in the absence of a brain restart. Sounds to me like a big leap towards suspended animation. Of course, you can't be frozen below 0 C using this techique, because all your cells explode when the water freezes. Plausibly with some mild oxygen influx you wouldn't need to be below 0 C, though. " I think I'll wait a while before planning my interstellar trip, tho'.
Not really suspended (Score:2)
I think the article mentionned that without this drug people have been successfully revived after an hour with no ill effects. I think beyond an hour they tend not to even try. How long could you last with this drug? Someone needs to try this with a large mammal, a dog perhaps, and see how long he can hang out at just this side of 0degC and still be revived with this drug.
-josh
Re:Reminds me of System Shock 2 (Score:2)
Re:Freeze me (Score:1)
Re:Freeze Recovery (Score:2)
This has been addressed:
http://www.mailgate.org/sci/sci.cryonics/msg001
Newsgroups: sci.life-extension,sci.cryonics
From: Tom Matthews
Subject: Re: a different type of life extension?
Date: Tue, 20 Jun 2000 08:20:52 GMT
Organization: Longevity Unlimited
Lou Pagnucco wrote:
>
> Good information, Doug.
>
> Cryonic approaches to suspending animation (in hopes of revival
> in the future) involve the freezing of organs or organisms at liquid
> nitrogen temperatures which, although inhibiting most chemical
> activity, cause significant ice damage to the cells.
Not if you vitrify the patient, which is where the current research is
now heading.
> The type of
> "freezing" in your abstract must avoid this difficult to repair ice
> damage.
>
> It would be interesting to know how long an organism (i.e., hibernating
> ground squirrels) can tolerate this temperature.
The answer is: no more than one year (in fact mostly only one normal
length winter).
This is only reasonable. Why would evolution have produced anything more
robust than it needed?
And this is why all of these natural animal hibernation/freezing models
are quite useless for cryonics purposes.
> After all cryonic
> freezing advocates seem to believe that cryonic freezing will be
> required for many years. However, given the hyper-exponential increase
> in biotechnical knowledge, maybe just a couple of decades may be
> enough to get us to the point where we can cure nearly any known
> disease (or the problems of aging) - and reviving an organism kept
> relatively inert using the same techniques that these squirrels use
> seem much, much less difficult.
However, there will always be accidents/diseases/disorders that are
beyond our reach to repair and need some from of long-term suspended
animation if the inflicted person is to remain alive.
Vitrification research is proceeding slowly but surely to eventually
provide us with fully-reversible, long-term suspended animation.
Still, like any major operation it will never be 100% and I for one am
trying very hard to stay alive until the biotechnical advances in
life-extension for existing adults come forth, so that I don't every
have to be cryopreserved.
> Doug Skrecky wrote in message
> >Title
> > Freeze avoidance in a mammal: body temperatures below 0 degree C in an
> > Arctic hibernator.
> >Source
> > Science. 244(4912):1593-5, 1989 Jun 30.
> >Abstract
> > Hibernating arctic ground squirrels, Spermophilus parryii,
> > were able to adopt and spontaneously arouse from core body temperatures
> as
> > low as -2.9 degrees C without freezing. Abdominal body temperatures of
> ground
> > squirrels hibernating in outdoor burrows were recorded with
> > temperature-sensitive radiotransmitter implants. Body temperatures and
> soil
> > temperatures at hibernaculum depth reached average minima during February
> of
> > -1.9 degrees and -6 degrees C, respectively. Laboratory-housed ground
> > squirrels hibernating in ambient temperatures of -4.3 degrees C
> maintained
> > above 0 degree C thoracic temperatures but decreased colonic temperatures
> to
> > as low as -1.3 degrees C. Plasma sampled from animals with below 0 degree
> C
> > body temperatures had normal solute concentrations and showed no evidence
> of
> > containing antifreeze molecules.
> >
--Tom
Tom Matthews
The LIFE EXTENSION FOUNDATION - http://www.lef.org - 800-544-4440
A non-profit membership organization dedicated to the extension
of the healthy human lifespan through ground breaking research,
innovative ideas and practical methods.
LIFE EXTENSION MAGAZINE - The ultimate source for new
health and medical findings from around the world.
Re:Talking heads (Score:1)
Re:Not really Moderated (Score:2)
Military applications (Score:1)
Shurely the military want efficient revival methods as well (there usually happens a lot of not so fun stuff to soldiers bodies during warfare), but this could also be used to artificially increase divers tolerance for cold water. Imagine a diver swimming around in cold water, with a computer watching over bodily functions and automatically injecting small doses of EDTA in the bloodstream if the diver experiences cramps, loss of consciousness or other unwanted effects of cold water. This could make it possible to have divers stay much longer under water in a normal dry suit without damaging the mission (or the diver of course, if you care about those sorts of things).
Re:Arctic Rescue (Score:1)
A syringe of EDTA plus a barrel of an 18 yr old single malt Scotch.
Please excuse me while I lie down in the snow.
(By the way I think the traditional beverage for Saint Barrels is brandy)
I should definitely get around to getting my SB a barrel
Re:Freeze Recovery (Score:3)
Re:About freezing for life... (Score:1)
Aging appears corrolated with the speed of your metabolism. Body fuel (atp) is very reactive, just as any good fuel should be. It seems that carring it around create regular damage that has constantly has to be repaired. However, every so often an important piece of dna gets broken which reders that particular cell les efficient, but also all it upcomming child-cells.
It is no surprise in that case that that all 100+ year elders describe they diet as 'frugal'.
The second component relates to a protein that repairs the buffering tips of the dna string after each copy. That particular protein is only present in the 'immortal' cells, sperms, ovulas and associated gametes. In other cell, copying strips some length of the buffers each time until it eats important dna code.
Lowering the body temparature stops problem one and, since a doubt cells can split in such cold conditions, would also stop problem two: effective body suspention.
As far as consciousness goes, if your brain can't process, you can't be concious. It would fell similar to passing out on boze: you would be terribly confused about where you are, but with a reason.
-
Re:Freeze Recovery (Score:1)
Is going below 0 totally necessary? (Score:1)
For a 60 year trip, the time it might take for a nuclear impulse rocket [nasa.gov] to reach the nearest stars, it wouldn't kill the crew if there bodies aged 6 years.
I guess everyone focuses on freezing because they want to come back in a thousand years and fight those damm dirty apes!
Re:Life for life? (Score:2)
Do you ever wash your hands? Every time you apply soap, you're killing millions of bacteria. Odds are that some activity in your daily life ultimately results in the death of some animal (even if you're a vegan). I, personally, draw the line at humans. That is, if you're human, you have a fundamental right to live. Otherwise, it's nice, but I won't worry about it. If another animal is proven to be sentient, then I'll include it. Until then,sorry.
Re:Why would people from the future unfreeze you!? (Score:2)
1. Being alive and well but having a gorilla body.
2. Being alive and well and finding yourself in culture whose language you don't know and conventions you cannot grasp. If its 1million years into the future you may never even come close to understanding what life means to them and you'll end up in a cage somewhere.
3. Half-dead coma state, coming in and out for a few hundred years.
4. Finding yourself in a robot body that has about 1% functionality of the human body, etc.
Other than spacetravel this stuff is useless (Score:2)
Its a scam and a fraud, ice crystals will make you unrepairable regardless. Even the finest nanomachine cannot know exactly where this broken neuron went and so on. If perfected, you would be lucky to be functionally retarded. Why don't you ever hear about the hundreds of animals that should have been frozen now side by side with the humans? Would you like to be the first one they tried to bring back? Unless you're bringing a few gorillas, chimps, and a few hundred mice along with you, you'll be the guinea pig. Be scared, some things are worse than death.
I'd much rather see more articles and work done on short time hibernation for spacetravel that lasts maybe 6 months to a year and work your way up. And if its ever perfected then you can move up to humans.
Just the fact that these companies start with humans and shrug when you ask how exactly are they going to revive a rotted then frozen corpse should make you very suspicious.
Re:Freeze Recovery (Score:1)
Maybe we can thaw out Walt Disney... (Score:2)
I think if we were to thaw him out, Disney could get a lot of people into the parks to see him!
--- Speaking only for myself,
Re:Other than spacetravel this stuff is useless (Score:1)
As for whether cryonics is a scam, isn't it a bit too early to tell? After all, isn't the premise of cryonics that medical technology 50-100 years in the future will be able to repair the freezing damage? How do you know what future medicine can/cannot do?
Admittedly, I think the odds are fairly low (< 1%) that current patients will be revived with > 90% fidelity (however you define the term.) within the next 100 years. However, all existing cryonics organizations point out that they don't if or when you will be revived, if at all, nor how well your identity will be recovered. So if you sign up anyway, and you are not successfully revived, how have you been defrauded?
At worst, I see cryonics as a form of religion--instead of resurrection by God, some cryonicists expect to be revived by the benevolent nanotechnologists of the future. But I don't think that makes them scam artists or frauds.
Finally, anyone familiar with the finances of cryonics organizations will tell you that cryonics is a terrible way to make money, even assuming it is a scam. I don't know what the exact numbers are, but less than 700-800 people have signed up to be frozen in the 38 years since the Robert Ettinger published The Prospect of Immortality (the first book to seriously propose cryonics.) Of those less than 100 have been frozen. [transhumanist.com] Historically, most people who work for cryonics organizations are volunteers or make little money. For example, the December 1990, Cryonics magazine reported that the Board of Directors of Alcor voted a 25% pay cut for all of the staff, so they could keep their budget balanced. Many of the Directors are also on the staff. The salaries after the cut ranged from $22,500 annually for highest paid full-time employee (the President) to $14,400 for the lowest-paid full-time employee.
Re:Freeze Recovery (Score:1)
Re:Talking heads (Score:1)
Does that mean they have to cut the head off another body in order to sew mine on? I don't think that's very nice. Maybe a robotic body would be just as good.
Re:Why would people from the future unfreeze you!? (Score:1)
A mistake!?! (Score:1)
Re:Reminds me of System Shock 2 (Score:1)
Re:Uploading debate (Score:1)
Has anyone read the book "Heart of the Comet"
In it, one of the main characters dies, but its "uploaded" into the computer. they then acknowledge that this is no longer who they knew but a "copy" of the person.
If your conciousness is dupicated, it isn't you; in the same way that if you close yourself, that clone isnt you, is it? its a copy of you.
something to think about
Re:The next step. (Score:1)
Re:Talking heads (Score:1)
Re:Freezing doesn't truly burst cells... (Score:1)
Re:About freezing for life... (Score:1)
Nick
Why would people from the future unfreeze you!? (Score:5)
Re:About freezing for life... (Score:3)
Worse yet, you could be stuck in that dark tunnel between your body and "the Light" for 1000 years. Sure it's fun to go sliding through it really fast, but after a few decades, it gets rather boring just sitting there watching the souls go by.
ummm, no (Score:1)
Life for life? (Score:1)
Re:Freeze Recovery (Score:1)
Human popsicles? Where would the wooden stick go? (ouch...)
The next step. (Score:1)
For example, salt water freezes at a lower temperature than pure water, but not really low enough to be significant here. It seems to me that what they need to develop is something that would would get into all of the water in the cells, and lower its freezing point. I'm sure this is easier said than done, but it seems like that could break down one of the main barriers in cryonics.
Of course, they would probably also have to develop another injection to be given during the revival process to remove this from the body, but I suppose that can wait until they're actually ready to start thawing people out.
And after the rat exploded... (Score:1)
And after the first lab rat exploded in a frozen mass of blood and guts (like when taking the entire blast of a double barrel at point blank in Quake 1), the scientists said:
"Huh huh. That was cool. Do it again. Make him explode. Now, use FIRE FIRE".
Save the lab rat campaign anyone?
Re:Freeze Recovery (Score:1)
Possibly Practical Applications (Score:2)
The article mentions using this to revive victims of hypothermia, but try this one on for size. The patient is in deep in shock for no apparent reason. Lab tests will tell for sure what's going on. It could be anaphylaxis. Could be poisoning, or something else. The doctors don't know what's causing it or how to counteract it. The patient will be dead inside of five minutes, but the lab tests will be ready in fifteen minutes at the earliest--if they're lucky and depending on which test shows positive. What do they do? Chill the patient rapidly to 16 degrees C and buy themselves some time. The lab tests come in, the doctors ready whatever treatment is appropriate--adrenallin and cortico steriods in the case of anaphylaxis--and revive the patient with the drug in the article.
I dunno how practical this would really be. Still, based on my own near death experience, I would certainly consider freezer burn to be an acceptable side effect of such a treatment.
Re:The next step. (Score:1)
Looks like Dr. Forrester might have had something there when he swapped Frank's blood for antifreeze..
Sure.. They called him mad.. but THEY'LL BE SORRY!!!
(2 karma for the episode in question..
Your Working Boy,
Re:The next step. (Score:2)
Interesting side note, the movie Iceman [imdb.com] didn't just ignore the issue of cryoprotectants; they came up with a clever explanation. The caveman had a habit of eating a certain type of flower that acted as a natural cryoprotectant, which saved his cells from bursting, thus allowing him to be revived after thousands of years. That was a pretty good flick; it had a surprisingly intelligent script.
Why the hell is everyone talking about cryonics? (Score:1)
Re:ummm, no (Score:1)
Re:Talking heads (Score:2)
from the www.cryonics.org faq (Score:2)
Call me a butcher, but... (Score:1)
Re:Freezing doesn't truly burst cells... (Score:1)
Milek
--
Re:Life for life? (Score:2)
For the rest of you, I have to rely on observed behavior and similarity of physiology. In that respect, the evidence that, say, dogs, are sentient ("capable of sensation and consciousness") is just as strong as the evidence that a pre-verbal child is sentient: both have sophisticted nervous systems, and behave in a way consistent with an internal emotional and (rudimentarily) intellectual experience.
Re:Talking heads (Score:1)
Stomachs, and livers, even skin - grows to have a taste for it's environment. People have had stomach transplants only to find they prefer the donor's favourite food - there was an article on this in New Scientist a few months ago.
It's a memory, and it's part of a person.
Re:first off... (Score:1)
-josh
Re:Freeze Recovery (Score:1)
The storage of sperm and eggs is only possible with highly delicate and specialized use of cryoprotectant agents to prevent freezing damage, Even so the freezing of sperm is only possible because there are so many that a reasonable death rate is still tolerable. The recovery rate of eggs (ova) is still extremely poor mainly because of the macroscopic size of these relatively large cells. Even 8-celled embryos are only still viable because all cells are equipotent and even if 7 die the embryo can still continue.
-- Paul --
Re:About freezing for life... (Score:1)
Nonsense! We have established no such thing because is it not even true! The cells *never* "explode. *If* the freezing rate is too fast then cell membranse may be ruptured since the water cannot escape into the interstitial spaces quickly enough and the small increase in density and the lack of membrane flexibility at low temperatures will cause such rupturing. However, even if human body were thrown into a Dewar of liquid nitrogen without any preparation, only the surface layer of cells would be able to cool that quickly.
In practice what happens is that cryoprotectants are perfused into the body during an operation similar to open heart surgery. These cryoprotectants enter all the cells through the capillaries of the circulation system and together with a controlled cooling rate, *all* the body's cells are prevented from rupturing. At the present time the trade-off involved is between a large cryoprotectant concentration which will totally prevent ice formation and yet will harm cells by toxic biochemical processes, and a smaller cryoprotectant concentration which will give recoverable toxicity but will not completely protect against freezing damage. Fortunately, there is a major effort underway at 21st Century Medicine [21cm.com] to find less toxic and more ice controlling cryoprotectants and that effort is having some success.
-- Paul --
Re:Life for life? (Score:2)
Re:Talking heads (Score:1)
z.
Re:Talking heads (Score:2)
But then, it seems kind of silly to me that someone thinks that by freezing themsleves without knowing how the whole process has to work, they'll freeze themselves "properly" in order to be revived. But hey, it's their money...
Talking heads (Score:2)
Re:Life for life? (Score:1)
The relevant characteristic is the presence of a sophisticated nervous system (or analogous structure) that produces an interal experience. As I said, it's impossible to know for sure whether other beings have such an experience, so we must judge based on the organism's behavior and on our knowledge of neurobiology.
For practical purposes, I do my best to avoid harming other chordates, and I won't deliberately harm invertabrates without good cause.
Re:Life for life? (Score:1)
I agree with you to a point, right up the part in bold, actually. I do my best not to cause ANY lifeform undue harm, death or suffering. I can't stop the fact that my breathing/washing/walking is destroying millions of bacteria, but I *CAN* pick up the bug on my floor with a little piece of paper and deposit him on the front lawn, rather than smashing him with my shoe or squishing him up in a tissue.
As far as sentience in animals...
I have witnessed both cats and dogs execute "planned" activity. One example would be along these lines:
Two dogs that live together with the same "master" are both given a treat at the same time. The first one gobbles up his treat in a few moments, while the second is taking her time in eating. The first dog runs to the window and begins barking loudly. The second dog drops her treat and also runs to the window to bark. At this point, the first dog stops barking and goes over and munches her treat.
He had a plan and he used it to deceive another for his own benefit. Sounds like sentience to me.
-The Reverend (I am not a Nazi nor a Troll)
ummm. (Score:1)
or what happened to Stallone in Demolition Man... Do you really want to end up in a world where sex is through a helmet and you are doomed to eat rat burgers
- Bill
Re:Why would people from the future unfreeze you!? (Score:1)
See, his wife was dying of some incurable disease, so he had her frozen. Now, to get her back he realized that he'd have to be frozen also, and that he'd somehow have to convince these future scientists that he was worth unfreezing.
So what he did was he started writing biographies of famous people of the 20th century. However, in each case he was careful to imply that each subject had imparted some vital insights to him that weren't to be put into the biography.
When future scholars read his works they fell for it and had him revived. However the state of the art medical facilities couldn't cure what killed his wife. They did however have relatively advanced spacecraft. To buy himself some time he took his wife (in her little frozen capsule) on a little trip around Pluto at near relativistic speeds. By the time he got back though...
I'm not intending to write a book review for something I haven't read in several years. I forgot the author's name and the book title, but the story stuck with me. If anyone read this gem please clue us all in. I think it dealt exceptionally with various "future travel" schemes.
AFP (Score:3)
Re:from the www.cryonics.org faq (Score:1)
Re:Talking heads (Score:3)
I don't know -- better head than dead.
(sorry)
--
Re:Life for life? (Score:1)
It works like this:
Two dogs are given treats at the same time. This happens every day. On of the dogs always inhales the treat, and the other always takes a little while to finish.
The first dog, now bored, ususally goes over to the window to check out the neighbor's poodle. One day, there's a strange man in the neighbor's yard. Dog goes nuts. Second dog drops treat to check out the situation. First dog sees the treat & snatches it.
If this scenario repeats itself, say, twice in one week, the first dog is now conditioned to bark at the window as soon as he's finished his treat. It's an experience thing. You're suggesting that the dog was licking his balls one day & thought to himself: "I know, if I can distract that bitch over there, I can get her treat!"
Really, it's not sentience any more than a mouse navigating a maze. It's not like the mouse thinks "Okay, that's two rights & a long straightaway...I must be near the outer wall of the maze now - I should turn left at the next intersection." He's simply repeating a sequence that's worked for him in the past.
US politics? (Score:3)
Freeze Recovery (Score:4)
The simple fact is, without nanotechnology to repair this vast damage, revival of all the 'frozen-in-nitrogen-suspended-animation' people is HIGHLY unlikly.
This is perhaps MUCH more applicable to transporting organs for transport, and perhaps in reviving hipothermia victims who havn't frozen solid yet.
Haiku (Score:4)
Though it's a great advancement
I won't beta test
Re:Why would people from the future unfreeze you!? (Score:1)
What about those toads from Canada... (Score:1)
Freezing Brains (Score:1)
Re:AFP (Score:1)
"
Yes I am interested.
Re:Freezing doesn't truly burst cells... (Score:1)
Re:Talking heads (Score:1)
Morons.
Water crystals (Score:1)
Hugo
Still haven't figured out suspended animation? (Score:1)
--
hmm.., I see a competive sport market for this. (Score:1)
And Walt Disney was never frozen either... (Score:5)
For a good review of the problems that need to be overcome to achieve suspended animation, see The Contributions of Low Temperature Science to Cryobanking and the Prospect of Suspended Animation for Manned Space Travel [graft-tx.com] by Michael J. Taylor, Ph.D., Debra J. Battjes Siler, M.S., John R. Walsh, Ph.D., Kelvin G.M. Brockbank, Ph.D. in Graft, May 2050, volume 3, issue 3 (also known as Volume 3, Issue 3, May/June 2000).
In my opinion, the currently most likely near term pathway to suspended animation lies in the use of vitrification. Vitrification involves introducing a sufficiently high concentration of cryoprotectant into an organ such that upon cooling, the fluid within the organ forms a glass instead of a crystal, thereby avoiding the problem of ice crystallization altogether. Please see this review article Organ Cryopreservation [neurocryo.org] by Greg Fahy, PhD. for a succinct review of the approach and numerous references to the available literature.
Finally, I would caution that the New Scientist is not a particularly discriminating science news source. For example, see the September 28, 1996 New Scientist article (p.22) regarding Olga Visser, a South African perfusionist at the University of Pretoria, who claimed that she had found a technique for successfully cryopreserving rat hearts [cryocare.org] at liquid nitrogen temperatures. In cryobiology circles, this is like someone claiming a cure for cancer. It is one of the "big problems" in cryobiology, that a number of scientists have spent decades trying to solve. Visser's claim could not be duplicated and were never published in a peer reviewed journal. Even worse, Visser later claimed that the same drug she used to achieve the holy grail of cryobiology, dimethylformamide, was also a cure for AIDS [slackinc.com].
Re:hear hear!!! (Score:2)
-- Give him Head? Be a Beacon?
Freezing damage (Score:2)
During cryonic freezing of humans they attempt to minimize this damage by replacing most of the water in your body with other fluids. Of course, it's difficult to replace all water so substantial damage is still caused. With current cryonic freezing techniques it will probably take some of Drexler's little helpers to repair the damage for reviving the individual.
----
Re:The 0 C barrier (Score:2)
Re:Talking heads (Score:2)
The best hope is to perfect long-term suspened animation by means of cryopreservation. In that process we know for sure that all processes are stopped and, once there, no additional damage will take place for thousands of years. If we could get human to low temperatures without any damage, then the problem of using this technique to prevent death would essentially be solved. Work done with ice blockers and new cryoprotectants in recent years auger well that this last problem is solvable within 10-20 years if with could only get sufficient funding for continuing the program. The amount of funding ($100M) is trivial in terms of what major government programs receive and especially in terms of the importance of the result (truly paradigm transforming), but nevertheless promotion of this effort is not going well. -- Paul --
Re:AFP (Score:1)
-- Paul --
Re:Freeze Recovery (Score:2)
I agree with you that reconstruction of badly damaged cells due to freezing by any conceivable technology, nano or otherwise is highly unlikely. However, that does not mean that fully perfected suspended animation cannot be and will not be achieved.
-- Paul --
Re:Freeze Recovery (Score:1)
-- Paul --
Re:About freezing for life... (Score:1)
When/if you wake up you will may be chronologically 1040, but you will be biologically still 40. Since antiaging and rejuvenation methods will almost certainly be perfected by that time, in fact, you will wake up as a biological 20 year old in the prime of health and abilities but with the wisdom and knowledge of your original age.
-- Paul --
Re:Freeze Recovery (Score:1)
I agree that revival of those nitrogen popsicles is a long shot. In the future we will probably focus on pre-conditioning the body before it is suspended. Repair after the fact is probably a lost cause.
Re:Teleportation as well (Score:1)
I'll agree, the same story goes for teleporation
SpirytFuck suspended animation (Score:1)
Yeah, well, (Score:2)
About freezing for life... (Score:1)
"Who is General Failure and why is he reading my hard disk ?"
frozen heads (Score:2)
Re:Talking heads (Score:4)
---
Freezing doesn't truly burst cells... (Score:5)
I personally recommend a read of the entire book (it's all online), but this chapter seems to have the most to do with the discussion.
hear hear!!! (Score:1)
FluX
After 16 years, MTV has finally completed its deevolution into the shiny things network
What are these people thinking? (Score:1)
Re:ummm. (Score:1)
mov ax, 13h
int 10h
Arctic Rescue (Score:2)
Re:Freeze Recovery (Score:2)
frogs and glucose (Score:2)
Daffynition: suspended animation (Score:3)
Uploading debate (Score:3)
One of the reasons I think the gradual method is better is because your own biological cells are constantly replacing themselves and yet one doesn't have an end of one's consciousness due to the gradual replacement. Like the "if you gradually replace every part of a car (or computer), it's still the same car (or computer)" thing. By replacing the neurons gradually, with functionally-identical technological counterparts, the other neurons could incorporate the replacements into the functioning of the brain, and hence one's consciousness, until the last biological one has been replaced and *you* are still there but with a non-biological brain.
The gradualness is what makes the difference, in my opinion. Another possible method of "soft"-uploading, although even more theoretical, is that if/when direct neuro-computer interfaces become available, there is something of a possibility that if someone were to spend enough time with their mind joined with the computer, their consciousness would gradually "spread" to the computer and remain active even once the original biological brain becomes inactive. (All totally theoretical for now, of course. :-) ) But once again, the gradualness of the process is what I think is the key to *you* being the one in the computer and not merely a duplicate of you. Just my opinion.
---
Re:Freeze Recovery (Score:2)