PZ Meyers has unreasonably high standards for 'relevant details.'
Well, he's a developmental biologist specialized in the vertebrate nervous system.
Demanding one millisecond total fixation time (with every atom being in precisely the same position as it was during life) is totally ridiculous. If you want to study intraneuron cell biology, sure, you need that, but for brain emulation, all you care about is the connection-ism of the network, and the long term statistical biases of particular neurons' synaptic connections (plus glial traits, naturally), which is (probably) visible from features many orders of magnitude more durable than the kinds of data he's talking about.
One millisecond fixation time might be an excessive requirement, but in order to perform an emulation accurate enough to preserve the self, you will probably need much more detail than the network topology and some statistics. Synapses have fine surface features that may well be relevant, and neurons may have relevant internal state stored as DNA methylation patterns, concentrations of various chemical, maybe even protein folding states. Some of these features are probably difficult to preserve and possibly difficult to scan.
EDIT:
As far as a reference goes, there's this study, in which they took a rat's brain, vitrified it, and examined it at fine detail, demonstrating "good to excellent" preservation of gross cellular anatomy.
Actually they vitrified 475 micrometre slices of the hippocampus of rat brains. It's no mystery that small samples can be vitrified without using toxic concentrations of cryoprotectants.
Moreover, the paper says: "Finally, all slices were transferred to the two wells of an Oslo-type recording chamber [ ... ] and incubated with aCSF at 34–37 C for at least 1 h before being used in experiments."
"Following initial incubation for 60 min or more at 35 C in aCSF to allow recovery from the shock of slice preparation, [ ... ]"
I'm not a biologist so I might be missing something, but my understanding is that this means that somehow ischemia is not an issue here, while it certainly is when dealing with a whole brain.
One millisecond fixation time might be an excessive requirement, but in order to perform an emulation accurate enough to preserve the self, you will probably need much more detail than the network topology and some statistics. Synapses have fine surface features that may well be relevant, and neurons may have relevant internal state stored as DNA methylation patterns, concentrations of various chemical, maybe even protein folding states. Some of these features are probably difficult to preserve and possibly difficult to scan.
The surface details we can r...
If you don't believe in an afterlife, then it seems you currently have two choices: cryonics or permanent death. Now, I don't believe that cryonics is pseudoscience, but it's still pretty poor odds (Robin Hanson uses an estimate of 5% here). Unfortunately, the alternative offers a chance of zero. I see five main concerns with current cryonic technology:
So I wonder if we can do better.
I recall reading of juvenile forms of amphibians in desert environments that could survive for decades of drought in a dormant form, reviving when water returned. One specimen had sat on a shelf in a research office for over a century (in Arizona, if I recall correctly) and was successfully revived. Note: no particular efforts were made to maintain this specimen: the dry local climate was sufficient. It was suggested at the time that this could make an alternative method of preserving organs. Now the advantages of this approach (which I refer to flippantly as "dryonics") is:
There is one big disadvantage of this approach, of course: no one knows how to do it (it's not entirely clear how the juvenile amphibians do it) or even if it would be possible in larger, more complex organisms. And, so far as I know, no one is working on it. But it would seem to offer a much better prospect than our current options, so I would suggest it worth investigating.
I am not a biologist, and I'm not sure where one would start developing such a technology. I frankly admit that I am sharing this in the hope that someone who does have an idea will run with it. If anyone knows of any work on these lines, or has an idea how to proceed, please send a comment or email. Or even if you have another alternative. Because right now, I don't consider our prospects good.
[Note: I am going on memory in this post; I really wish I could provide references, but there does not seem much activity along these lines that I can find. I'm not even sure what to call it: mummification? Probably too scary. Dehydration? Anyway feel free to add suggestions or link references.]