I correct my assertion; damage may begin in a minute or two such as going unconscious, but the more extreme permanent levels of damage take a bit longer:
In severe cases it is extremely important to act quickly. Brain cells are very sensitive to reduced oxygen levels. Once deprived of oxygen they will begin to die off within five minutes.
The longest human survival without breathing is 80 minutes.
If you’re referring to Anna Bågenholm, you’re wrong; she survived in an air pocket and did not freeze but was hypothermic. Hypothermic techniques are already used in medicine, with no visible uptick in cryonics support.
How badly would the brain have to be shredded at microscale until cryonicists wouldn’t sign up?
I don’t think anyone bothers past a day or so post-death, by which point decay processes have set in.
Why no one would cut brain into pieces and preserve it chemically, squishy pieces in a jar style?
Why would you do that? We don’t know where the exact crossing line is, so every additional level of degradation and poor preservation increases the chance of failure.
If you mean chemopreservation or plastination, the answer is, I think, historical convenience: fast freezing and then vitrification were developed long before fast versions of either of the former. Existing techniques of chemopreservation or plastination still don’t scale to an entire brain the way cooling can; although Darwin’s been working on a proposal for plastination+cryonics, and the Brain Preservation Prize should be getting evidence allowing direct comparison, so ‘brain in a jar’ methods may yet work out. (Cold comfort for anyone who already has died or will soon die, however.)
I correct my assertion; damage may begin in a minute or two such as going unconscious, but the more extreme permanent levels of damage take a bit longer:
-- http://en.wikipedia.org/wiki/Cerebral_hypoxia
If you’re referring to Anna Bågenholm, you’re wrong; she survived in an air pocket and did not freeze but was hypothermic. Hypothermic techniques are already used in medicine, with no visible uptick in cryonics support.
I don’t think anyone bothers past a day or so post-death, by which point decay processes have set in.
Why would you do that? We don’t know where the exact crossing line is, so every additional level of degradation and poor preservation increases the chance of failure.
If you mean chemopreservation or plastination, the answer is, I think, historical convenience: fast freezing and then vitrification were developed long before fast versions of either of the former. Existing techniques of chemopreservation or plastination still don’t scale to an entire brain the way cooling can; although Darwin’s been working on a proposal for plastination+cryonics, and the Brain Preservation Prize should be getting evidence allowing direct comparison, so ‘brain in a jar’ methods may yet work out. (Cold comfort for anyone who already has died or will soon die, however.)