I explain Suda's experiments and their limitations in the latter part of this video:
http://video.google....9858&q=cryonicsSuda's experiments are not directly relevant to cryonics as currently practiced because Suda used much less cryoprotectant, and cooled to high sub-zero, not deep sub-zero, temperatures. At a temperature of only -20 degC, the cells surviving between ice crystals would still be in a liquid state in a freeze-concentrated glycerol solution. Because the cells are not in a solid state (not below the "glass transition" temperature), chemical deterioration still occurs. The viability of tissue degrades over years. But he was still able to get some return of electrical activity even after 5 years of storage.
If he cooled to lower temperatures with the concentration of glycerol he used, he could still recover "unit" (cell) function, but not integrated EEG of the whole brain. Too much ice forms at low temperatures, disrupting long-range tissue connections. If he had increased the glycerol concentration to reduce ice damage at deep sub-zero temperatures, he would have found it to be toxic. It's the infamous ice-damage vs. toxicity-damage tradeoff of cryobiology.
Present brain vitrification technology still cannot preserve viability in the conventional sense. It is not possible to rewarm brains cryopreserved with current technology, perfuse them with blood, and recover EEGs as Suda did. If that were possible, that would be reversible brain preservation, the Holy Grail of cryonics. Unfortuately we are not there yet. What is being achieved now is hopefully enough preservation of structure and chemistry to avoid "information theoretic death." In other words, hopefully the damage that is occuring is not erasing memory. If so, then restoration to full health while recovering the original person is doable in principle with foreseeable technology.
Cryonicists talk about Suda's experiments because they show in a very extreme way that brain function can be recovered in actuality, not just in theory, if chemistry and structure is preserved sufficiently well. In other words they show that brains can be "turned off and then back on," even after days or more stored in a freezer. We already know that's possible according to laws of physics, but few people respond to purely rational arguments about these things. I know a medical doctor cryonicist who knows more physics than the average physicist. What got him into cryonics? He saw dogs lie clinically dead on a table for four hours packed in ice like cold meat, and then later revived to full health. Even if not directly relevant to cryonics, such experiments address on a gut level one the deepest instinctive objections to cryonics: The fallacious belief that life is function, not structure.
