19. August 2014 · Comments Off on Ultrastructural Signatures of Information-Theoretic Death · Categories: Cryonics, Death, Neuroscience

On October 11, 2013, the Wall Street Journal featured a cover story about the unintended consequences of Norway’s long-time insistence on “plastic graves” (“Grave Problem: Nothing is Rotting in the State of Norway”). You see, after World War II the Norwegians wrapped the dead in plastic prior to burial and now they are faced with…corpses that are not decomposing. Since cemetery real estate is scarce in Norway this creates a rather complicated and sensitive problem. One of the solutions is to poke holes in the ground and plastic to inject a lime-based solution to accelerate decomposition.

Not many people would expect the brains of these plastic-preserved Norwegian corpses to be in pristine condition at the ultrastructural level but this strange story does illustrate that decomposition is a process that is highly sensitive to variables like the presence of oxygen, water, microorganisms, and temperature. Of course, some of these variables are related. When temperatures are lower there will be reduced microbial activity. As a consequence, at cold temperatures the rate of decomposition can be even slower than what one would predict based on the decrease of the brain’s metabolism alone. Cold ischemia is not just warm ischemia slowed down (and vice versa).

My company, Advanced Neural Biosciences, Inc., is currently collaborating with Alcor to produce a series of electron micrographs of brain tissue exposed to very long times of cold ischemia (0 degrees Celsius). One of the reasons we are doing this project is to bring actual data to the decision making process concerning the question when to accept and when no longer to accept a patient who has been stored at low temperatures prior to contacting Alcor for cryonics arrangements.

Ultimately, what we are looking for is an ultrastructural signature of “information-theoretic death.” This presents a formidable problem because information-theoretic death is not an unambiguous identifiable property of an image but concerns our best guestimate about how much structure a future technology might still be able to infer from a given state of damage. For existing patients and members who want to be preserved under any conditions this is not a directly relevant question (the future will tell). But when you have to make a decision whether to accept a third-party “post-mortem” patient, arbitrary decisions have to be made because Alcor simply cannot accept every case brought to its attention.

We have now produced electron micrographs of up to 1 month of cold ischemia. When we shared these 1 month images with the Alcor Research and Development committee one member remarked that he “would not have guessed that so much structure could remain after one month.” When we presented an image from this series at a recent conference, attendees were also surprised about this level of preservation.

Of course, this is not the end of the story because a patient with such a long period of cold ischemia will still need to be cooled to cryogenic temperatures for long-term care and a “straight freeze” on top of such extensive ischemic damage could tip the balance towards informationtheoretic death. These results raise one interesting possibility, however. If the damage of a straight freeze is a lot worse than the damage from moderate times of cold ischemia, cryoprotecting the brain (or both hemispheres separately) by soaking it in cryoprotectant could be a superior protocol for a select number of Alcor cases. There is still much to be learned.

Originally published as a column (Quod incepimus conficiemus) in Cryonics magazine, November, 2013

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