Would you mind summarizing the summary? :) I'm not familiar with the science but would like to understand the gist of why the work of those two competitors is important.
Sure. Basically, there are two groups, each of which has made a major contribution:
1) Shawn Mikula and his group. They have made substantial progress (some would say, almost solved) of how to make the neuronal connections and other brain structures such as white matter tracts in a full mouse brain traceable using electron microscopy. Electron microscopy is the lowest level of imaging currently feasible, and can clearly resolve structures that are thought to be key to memory such as synapses.
2) The 21CM group, including Robert McIntyre. They have developed a totally new method of preserving a brain that should yield both highly practical and technical sound preservation. In a sense it combines the methods discussed by Gwern in his article Plastination vs Cryonics, because it first uses a method traditionally associated with "plastination" (glutaraldehyde perfusion), and then uses a method traditionally associated with cryonics, i.e. perfusion with a cryoprotective agent and then low temperature storage and, presumably, vitrification, which means that damage from ice crystal formation should be avoided and the brain should turn a glass state.
Apologies if this is still too technical and I'm happy to answer any follow-up questions. Many key steps remain but this is progress worthy of celebrating and, in my view, supporting.
it first uses a method traditionally associated with "plastination" (glutaraldehyde perfusion), and then uses a method traditionally associated with cryonics, i.e. perfusion with a cryoprotective agent and then low temperature storage and, presumably, vitrification, which means that damage from ice crystal formation should be avoided and the brain should turn a glass state.
Is this related to the new SafeSpeed process used in http://lesswrong.com/r/discussion/lw/m8g/link_persistence_of_longterm_memory_in_vitrified/ ?
No, I don't think so; although I don't know exactly what is in the 100 ul of "Equilibration Solution" and "Vitrification Solution", I highly doubt that they cross-link any proteins like glutaraldehyde does. Because C. elegans are so small, it is much easier for standard cryoprotectant agents to diffuse across them. So, methods to stabilize blood vessels and tissue parenchyma prior to cryoprotectant agent perfusion, which is valuable in larger animals such as pigs, are not necessary in C. elegans.
What are the advantages to the hybrid approach as compared to traditional cryonics? Histological preservation? Thermal cracking? Toxicity?
As I understand it, the major advantage is that doing the cross-linking first (e.g. w glutaraldehyde) saves you time and maintains blood vessels so that traditional cryoprotectants can diffuse more widely across brain tissue. It also may allow easier validation of the cryopreservation protocol, because you don't have as many dehydration issues.
Brain Preservation Foundation President Kenneth Hayworth just wrote a synopsis of the recent ongoings from the major two competitors for the BPF prizes. Here is the summary:
Brain Preservation Prize competitor Shawn Mikula just published his whole mouse brain electron microscopy protocol in Nature Methods (paper, BPF interview), putting him close to winning the mouse phase of our prize.
Brain Preservation Prize competitor 21st Century Medicine has developed a new “Aldehyde-Stabilized Cryopreservation” technique–preliminary results show good ultrastructure preservation even after storage of a whole rabbit brain at -135 degrees C.
This work was funded in part from donations from LW users. In particular, a grant to support the work of LW user Robert McIntyre at 21st Century Medicine that the BPF was able to provide has been instrumental.
In order to continue this type of research and to bolster it, BPF welcomes your support in a variety of different ways, including awareness-raising, donations, and volunteering. Please reach out if you would like to volunteer, or you can PM me and I will help put you in touch. And if you have any suggestions for the BPF, please feel free to discuss them in the comments below.