It seems like the approach of cooling the organism to −30C at 350MPa, and then raising pressure further to ~600Mps to freeze it could actually solve that. As far as I understand, the speed of diffusion in water it far slower that the speed of sound (speed of sound at 25C is 1497 m/s, while diffusion coefficient for protons at 25C is 9.31e-5 cm^2/s, which corresponds to 1.4e-4 m/s − 8 orders of magnitude less), which is the speed of pressure gradient propagation. So if we use raising pressure as a way to initiate phase transition, it will occur nearly simultaneously everywhere, and the solutes won’t have time to diffuse anywhere.
ETA: I just realized that since diffusion propagates according to inverse square law, while sound is linear, they should be compared to each other at the shortest distance possible. So I checked the time it takes for a proton to cover 0.1nm (hydrogen atom diameter) in water − 5.37e-13s, which gives us 186 m/s. It’s far greater than the original number, but still an order of magnitude smaller than the speed of sound. And if we take 4nm (the thickness of a cell membrane) we have 8.59e-10s—only 4 m/s, so it decreases very quickly, and we’re pretty much safe.
Statements like this make me want to bang my head against a wall. No, it is not. Brain is a collection of neural and glial cells, the role of which we only partially understand. Most of the neurons are connected through various types of chemical synapses, and ignoring their chemical nature would fail to explain the effects of most psychoactive drugs and even hormones. Some of the neurons are linked directly. Some of them are myelinated, while others are not, and this is kinda big deal, since there’s no clocking in the nervous system, and the entire outcome of the processing depends on how long it takes for the action potential to propagate through the axon. And how long it takes for the synapse to react. And how long the depolarization persists in the receiving neuron. And all of that is regulated by the chemistry of regulating gene expression patterns. And we’re not even talking about learning and forming long-term memories, which are due to neuroplasticity, entirely controlled by gene expression patterns. It’s enough to suppress RNA synthesis to cause anterograde amnesia—although it will also cause some retrograde amnesia too., since apparently merely using neurons causes them to change.
Also, C. elegans doesn’t even have a brain; it has ganglia.
Look, I understand that this is some interesting research, but calling it “brain uploading” is like comparing the launch of a firework to interstellar travel: essentially, they’re the same, but there are couple of nuances.