As this article points out, despite the fact that much is left to be determined in neurobiology, based on the current evidence and understanding it is reasonable to expect that cryopreservation of the brain via vitrification preserves the data of the mind. When considering cryonics as an end of life option this is the critical question: the whole point of the exercise is to prevent the pattern that is you from decaying away to nothing. While that pattern continues to exist, most likely encoded in the molecular structure of synapses, a preserved individual can wait for as long as it takes for technology to advance to the point at which restoration is a possibility.
Can any technology, even in principle, preserve the unique features of an individual's mind? We agree there is more to the mind than the synaptic connections between neurons. The exact molecular and electrochemical features of the brain that underlie the conscious mind remain far from completely explored. However, available evidence lends support to the possibility that brain features that encode memories and determine behavior can be preserved during and after cryopreservation. Cryopreservation is already used in laboratories all over the world to maintain animal cells, human embryos, and some organized tissues for periods as long as three decades. When a biological sample is cryopreserved, cryoprotective chemicals are added and the temperature of the tissue is lowered to below the glass transition temperature (typically about -120 C). At these temperatures, molecular activities are slowed by more than 13 orders of magnitude, effectively stopping biological time.
Although no one understands every detail of the physiology of any cell, cells of virtually every conceivable kind are successfully cryopreserved. Similarly, while the neurological basis for memory, behavior, and other features of a person's identity may be staggeringly complex, understanding this complexity is a problem largely independent of being able to preserve it. Direct evidence that memories can survive cryopreservation comes from the roundworm Caenorhabditis elegans. For decades C. elegans have commonly been cryopreserved at liquid nitrogen temperatures and later revived. This year, using an assay for memories of long-term odorant imprinting associations, one of us published findings that C. elegans retain learned behaviors acquired before cryopreservation. Similarly, it has been shown that long-term potentiation of neurons, a mechanism of memory, remains intact in rabbit brain tissue following cryopreservation.
It is easy to dismiss controversial practices such as cryonics and gloss over the research surrounding them, but we should remember and even respect that prevailing views are often shown to be incorrect, and that what is impossible now may be possible in the future. For example, Ignaz Semmelweis, the father of germ theory, was widely ignored when he proposed in the 19th century that nurses and doctors should wash their hands before treating patients. Even today, physicians are frequently incorrect when predicting outcomes in end-of-life situations. Cryonics deserves open-minded discussion, as do mainstream efforts to understand the nature of consciousness, preserve human tissue and organs for life-saving transplants, and rescue critically injured patients by understanding the boundaries between biological life and death.