jacquesm is right, there's no actual scientific breakthrough here. We already know glutaraldehyde does a good job of preserving synaptic structure, that's why we have used it to fix brains for electron microscopy analysis for roughly a century. I guess it's cool that you can freeze a glut-fixed brain and then unfreeze it and that won't have a dramatic effect on the structure. I'd be interested to know how quantitative their analysis was. Absence of evidence (of deformed synapses) is not evidence of absence. But anyways the synaptic ultrastructure probably isn't everything. It's necessary but not sufficient.
The comments suggesting that this is unimportant are pretty silly. People have been objecting to cryonics on the basis that it hasn't been proven beyond a doubt to preserve fine structure, versus only having had a reasonable set of evidence to preserve fine structure. They have objected on the basis that proven methods of preservation in small scale tissue samples hadn't been rigorously demonstrated to work in large organs. Now that the fine structure and scaling doubts are dispelled, they move on to objecting for other reasons, and even suggest that it was obvious in hindsight that the fine structure was preserved, or that methods would scale.
Denying that cryonics is relevant or useful or a valid area of research and development because no-one has yet completely implemented the full loop of technologies for reversible full body cryopreservation is missing the point. (But note that it has been done for a single organ, which was transplanted, and functioned).
The point is that we could be saving lives, and we are not, largely because of irrational objections that are not really based on technological or scientific positions, but grasp at a those positions as a shield for the real nebulous feelings on the matter.
The reversal of cryonics in the future has been written on extensively. There are very detailed treatments of what would be required. There is no sound reason to think it impossible; it's just a matter of sufficient control over chemistry and biochemistry. If you believe that there is some sound reason that it is impossible, then publish a paper - it would be influential if correct, because it would demolish the work of much of the cryobiology community in their initiatives to create reversible cryopreservation of organs and tissues.
Here is the paper for this research by 21st Century Medicine: "Aldehyde-stabilized cryopreservation":
Cryopreservationist walks into a bar. Goes 'Hey, everybody, pay me $50 and I'll show you a fantastic trick, I take your watch, put it in a bag, smash it up with a hammer, then open the bag and out comes your watch'. Fascinated a number of patrons sign up and pay their $50, hand over their watches.
Audible gulps as the watches go into a nice silver velvety bag and a very large hammer smashes down on the bag with the bar serving as temporary anvil.
The bag with the remains of the watches gets carefully pocketed and some of the money goes towards ordering a round of drinks for everybody.
So, how about my watch, asks one of the people that handed over his watch and his money. "Oh, that's the hard part, I haven't really studied that yet, come back in a few 100 years and I might have your watch again. But I'm getting better at smashing watches, that's for sure."
> The point is that we could be saving lives, and we are not, largely because of irrational objections that are not really based on technological or scientific positions, but grasp at a those positions as a shield for the real nebulous feelings on the matter.
What makes you believe that we could be saving lives?
This analogy makes little sense. Nature is the man with the hammer. After you die he smashes your brain to bits. There is nothing left. You cease to exist forever.
Cryopreservation is an attempt to stop the man with the hammer. By preserving your brain, you give yourself a chance that you can be revived, if technology advances that far. Which certainly seems very likely.
It is a tragedy that the majority of people who die are not cryopreserved. It's absolutely silly. Even if there is only a small chance it will work, it is still absolutely worth doing.
> The bag with the remains of the watches gets carefully pocketed and some of the money goes towards ordering a round of drinks for everybody.
I might have misunderstood this bit (in which case, oops). I see way too many people making the assumption that cryonics is somehow primarily profit motivated. Taking money out of the cryonics trust to "buy drinks" would potentially cost the lives of patients, as the organization must remain stable in addition to the revival being achievable to begin with. The incentive is towards long term savings.
> So, how about my watch, asks one of the people that handed over his watch and his money. "Oh, that's the hard part, I haven't really studied that yet, come back in a few 100 years and I might have your watch again. But I'm getting better at smashing watches, that's for sure."
This analogy doesn't make much sense to me. Cryonics is about trying to prevent something that will inevitably be smashed from being smashed as badly. Saying cryonics is about smashing things is like saying seat belts are about cars crashing into each other.
> What I didn’t do with my experiments in aldehyde-preserved brains was claim that I was preserving all the information necessary for nervous system function. I was quite aware that I was chemically nuking all the proteins in the tissue; I was washing out most of the chemistry; I was destroying most of the physiological information to preserve a structural skeleton of what was there, so I could see the physical arrangement of the pieces. Nothing more.
The question of whether the physical structure is enough to preserve the information that makes you you is the key thing, and Myers is right to say we should be trying to figure out how to read the information off of very small brains.
On the other hand, if you think that the physical structure is sufficient (I don't) then figuring out how to preserve whole human brains is pretty important. There's a long time to figure out how to read the information off the preserved brains, but any unpreserved (or improperly preserved) ones are gone for good. So I see why Hayworth etc are interested in high-quality preservation of larger and larger animals and aren't focusing on the reading portion.
"I'm more inclined to believe their goal is to pocket lots of money exploiting people’s fear of death. ... Fruit flies and nematodes won’t pay them a substantial annuity to have their brains vitrified and stored, and their gratitude upon being resurrected wouldn’t be at all remunerative."
I've met Hayworth, this really doesn't fit him. He is genuinely interested in better preservation methods as a way to fight death. As a neuroscientist working in connectomics his association with cryonics only hurts him professionally.
His criticism bad (as ever), since he assumes all information needed for nervous system function is the same as all information needed to replicate a given nervous system. Most of the information needed for function in any system is generic across similar systems. We are only interested in the information that is specific to the individual.
This technique is useful for general neuroscience purposes, yes. My point was just that it isn't what is critical to preserve for the sake of cryonics.
PZ made the usual error that most biologists make: if it's busted, the information isn't there and can't be recovered. It's dead. The vital spark has departed. It's soul has gone to heaven. Vitalism is alive and well.
Ask anyone who owns a computer if you can recover information from the hard drive of a busted computer.
Aldehydes covalently bond and crosslink the proteins and irreversibly kill all of the fixed cells. There is zero hope that this provides a solution to cryopreservation except in the slice it up and look at it under the microscope sense.
> Aldehydes covalently bond and crosslink the proteins and irreversibly kill all of the fixed cells.
That is the textbook answer, however these bonds are only "irreversible" as a matter of biochemistry. You can actually break any chemical bond by increasing the temperature enough. The problem for our purposes is that this means destroying the structure.
> There is zero hope that this provides a solution to cryopreservation except in the slice it up and look at it under the microscope sense.
The trick to reversing the bond without damaging the structure would be in delivering high enough amounts of energy with high enough precision to have only the intended effects. This may or may not be physically possible. However, to rule out the possibility completely, we would need to consider a wide variety of physical interactions that are well outside the range of biology and wet-solvent chemistry, in addition to the full spectra of potential biomimetic and biological approaches.
Good luck. When you make an imine with an aldehyde the principal mechanism of irreversability is that a stray reductant (available in spades in biochemical settings) takes the imine down to a primary amine. (This is not found in most textbooks, you just have to know that). Now, a primary amine is a relatively stable covalent bond, and getting selective deamination is going to be especially difficult since there's plenty of amines around. Not the least of which is the other side of the lysine that the aldehyde attached to in the first place.
True! But slicing it up and looking at it under microscopes is, in fact, the most likely means of restoring cryopreserved brains, either as computer simulations or as nanobot-constructed replicas. Doing it this way is easier because such techniques could handle cases where molecules are damaged in ways that make them not function but which make it obvious (from a good microscope reading) what they were before.
What I find confusing is that (from a quick skim) there's no mention on how easy it would be to actually bring back the brain in, say, 50 years. Does this method make reviving brain tissue easier?
The breakthrough here was injecting a poison that makes revival impossible but allows freezing with synaptic structure intact. Then hypothetically you can slice and scan the brain and simulate it later when computers are powerful enough.
Personally that seems more likely tha figuring out a new reversible freezing process.
I'll give you some engagement. I really think it is sad that you see this as a 'great scientific achievement' when in actual fact nothing of note has been achieved.
The whole article reads like a puff-piece pretending this is a major breakthrough when in fact as far as I can see it not much of note has been achieved, yes, it's a mammal but certain types of frogs have been known to be able to freeze and thaw and their neurological systems are working just fine afterwards. In this case all we have is some visual inspection which makes the claim that the brain has been recovered a bit doubtful, it's not as if a rabbit using that previously frozen brain is hopping around. (That probably would be a breakthrough.)
Cryopreservation, uploading, life extension technology and related fields are for the most quack science taking money from the gullible (or their estates) and spending it on un-productive areas of research. I sincerely wished that HN would stick to discussing things with a bit more solidity, if we afford these subjects the amount of space their proponents would like then HN would go the same way as renewable energy fora that allowed 'zero point energy' enthusiasts to run unchecked. I'm happy for you that you wish to live for ever (who doesn't?) and that you believe that in your lifetime we'll see a major change in this respect but I'm a bit tougher to convince and I've seen enough bs during my lifetime to solidly vote against giving this stuff more airtime than it already has. Historically, anybody that tried to peddle life eternal turned out to have been lying.
FWIW you're going to die, get used to it and make the most of the time that you have. If and when the future dictates otherwise you'll be able to adjust with grace and on the off chance that it does not you'll be happy you followed my advice.
That's a bit insulting of you, to presume that anyone who forms an opinion of Cryonics beyond "It's Quack Science" is only interested in "living forever", and not to be taken seriously.
The essence of your argument is circular: it doesn't work because it's quack science, and it's quack science because it doesn't work - but it doesn't matter, because you're going to die anyway.
What a cop out. One would think you got your information on Cryonics from watching an old VHS of "The Re-Animator"
> One would think you got your information on Cryonics from watching an old VHS of "The Re-Animator"
That's a bit insulting of you.
And to answer, no, I get my information from reading articles such as those linked, hence my comment on it.
I've seen enough of the groups pushing these kind of pieces to see them as no better than religious groups selling 'the afterlife' and associated goodies with zero chance of actually delivering on their promises. And just like those religious groups they always need a little bit more money.
It's quack science because none of it works. It will be science once someone can freeze a very small mammal (say a tiny rodent), keep it frozen for a while and then thaw that creature again and it will live a long and healthy life.
It will be science when someone scans a very small brain to a very high resolution, will build a functioning simulation of that brain in a computer to such an extent that the simulation exhibits all of the traits of the original.
Until then it's all just purposefully soft-balled problems that pretend to solve some crucial aspect of the whole chain without actually addressing the main problems head on, just enough 'progress' to keep the funding coming.
I make my living debunking bs and this stuff is - to me - a very high grade of it, all I see here is a cynical attempt at getting funding by for instance linking Alzheimer research to this group (which they have absolutely nothing to do with).
"It will be science when someone scans a very small brain to a very high resolution, will build a functioning simulation of that brain in a computer to such an extent that the simulation exhibits all of the traits of the original."
And that science will not happen until we have (among several things) the ability to stabilize a brain sufficiently (when no longer being used for its original purpose) to have a very high resolution scan performed and stored.
I would think getting this first part correct would be of the utmost importance. Scan resolutions will continue to improve for any number of reasons beyond this application.
It would appear that the primary subject of the OP is both quite relevant, and an important building block, allowing research to move further along this particular approach.
Given the state of computing power, this might happen first:
Become skilled at transplanting rat brains.
Raise identical twin rats.
Train one rat to run a maze.
Sacrifice the maze-running rat.
Stabilize its brain and scan it at high resolution.
Use an organ printer to create a duplicate of the rat brain from the scan.
Transplant the new brain into the living twin.
Put the chimera rat in the maze.
Observe the result.
Laugh maniacally.
What I get from reading the article and comments is that while the elements of the prize winner's solution have been available, the novelty is in their application.
Did someone already arrive at their solution, and simply not try to claim the prize money?
I don't know when it was first used, it's one of those protocols that every lab has sitting in an ancient three-ring binder. The procedure is essentially the same everywhere, with minor variations depending on the tissue you're working with, the stains, etc:
1. Knock the animal out somehow (usually isoflurane or similar)
2. Perfuse with Phosphate-buffered saline (PBS) followed by 2-5% Paraformaldehyde (PFA). You can also use glutaraldehyde, which is better for EM, while PFA is usually better for histochemistry
3. Rinse in PBS for a while
4. Drop the brains into sucrose solutions, let them sit there until they sink. Usually labs will have a few sucrose baths they like to use (e.g. start in 10%, then switch to 30%). Sucrose is the cryoprotectant here
5. Dunk in liquid nitrogen, coat with OCT, mount on cryostat and start sectioning
6. Go about your business staining, etc
The only novel thing here, really, is that they perfused the cryoprotectant instead of just letting the brains sit in it for a few days. Letting a rabbit brain soak up sucrose likely takes longer than a mouse, so perfusing would definitely speed up that step.
But it's a rather moot point, since fixed brains can chill in refrigerated PBS for a month or two. There's no rush once it's fixed ... that's the point of fixing. I'm with the other folks, this was really just a grab at some money imo. And fancy headlines. There is nothing interesting here.
Credentials: worked in neuroscience wet-lab for 5 years.
