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Cryonics FAQ 2: Science/Technology

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Archive-name: cryonics-faq/part2

See reader questions & answers on this topic! - Help others by sharing your knowledge
		    Frequently Asked Question List
		    Section 2: Science/Technology
		Last Modified Sun Jan 29 15:05:32 1995

(You can fetch cryomsg "n" by sending mail to with the 
subject line "CRYOMSG n", where "n" is a mesage number.  There is
more about this in the answer to question 8-2.  The index
to this FAQ list is cryomsg "0018.1".  )

Copyright 1993 by Tim Freeman.  See the end of Section 1 for
restrictions on redistribution.

2-1.  Has anyone been successfully revived from cryonic suspension?

No.  Fortunately, successful cryonics is a two-step process:
  (1) put the patient in suspension and
  (2) revive the patient from suspension.
For cryonic suspension to be worthwhile, we only need to master
step (1) right now and have reasonable expectation that we might
master step (2) later.

2-2.  What advances need to be made before people frozen now have a chance
      of being revived?  

A number of advances in basic areas of research such as medicine,
microbiology, engineering, and information sciences are required
before any serious attempt can be made to revive patients suspended
with current technology.  Nanotechnology, the design and fabrication
of molecular scale machines, is an emerging technology that will
probably be both necessary and sufficient for revival.

2-3.  Is there any government or university supported research on cryonics

There was suspended animation research sponsored by NASA as late as
1979 at the University of Louisville, Kentucky.
2-4.  What is the procedure for freezing people?

Read an account of a cryonic suspension.  Briefly, circulation is
restored by CPR, and the blood is replaced by other substances that
prevent blood clots and bacteria growth and decrease freezing damage.
As this happens the body is cooled as quickly as possible to slightly
above 0 degrees C. After the blood has been replaced the body is
cooled more slowly to liquid nitrogen temperatures.

2-5.  How can one get a more detailed account of a suspension?

Cryomsgs 601 and 602 are The Transport of Patient A-1312 (28K bytes)
and cryomsgs 696, 697, and 698 are The Neurosuspension of Patient
A-1260. (35K bytes).  These messages give a first-hand description
of the initial stages of two suspensions.  

2-6.  Is there damage from oxygen deprivation during a suspension?

Not if the suspension happens under good circumstances.  One of the
big goals of the suspension procedure is to get the heart and lung
resuscitation (HLR) machine onto the patient as soon as possible, to
prevent this damage.  The barbiturates they give reduce brain
metabolism, as does cooling.  In a well done suspension, the damage
from oxygen deprivation should be minor.  In a more perfect world, the
suspension procedure would be able to start before legal death, which
should reduce the damage from ischemia even more because there
wouldn't be any time when the heart is stopped and the body is warm.

2-7.  Do memories require an ongoing metabolism to support them, like RAM in
      a computer?

No.  Here's a relevant quote, supplied by Brian Wowk:

        We know that secondary memory does not depend on continued 
        activity of the nervous system, because the brain can be 
        *totally inactivated* (emphasis added) by cooling, by general 
        anesthesia, by hypoxia, by ischemia, or by any method and yet 
        secondary memories that have been previously stored are still 
        retained when the brain becomes active once again.
Textbook of Medical Physiology, Arthur C. Guyton, W.B. Saunders 
Company, Philadelphia, 1986

Thomas Donaldson says that brain waves of supercooled small animals
have been measured, and there are none, even though the animals still
have their memories after they are rewarmed.  He cites AU Smith, ed.
by Aubrey Smith herself, "Revival of mammals from body temperatures
below zero", pp. 304-368.

2-8.  If these frozen people are revived, will it be easy to cure them of
      whatever disease made them clinically die?

Repairing the freezing damage looks much harder than curing any
existing disease, so if revival is possible then curing the disease
ought to be trivial.  This doesn't include diseases that lose
information in the brain, such as Alzheimer's, mental retardation, or
brain tumors; in these cases, even if the disease were cured and the
person revived, the problem of replacing the lost information looks

2-9.  If I'm frozen and then successfully revived, will my body be old?

No.  Old age is a disease that ought to be easier to cure than the
freezing damage.

2-10. Why is freezing in liquid nitrogen better than other kinds of
      preservation, such as drying or embalming?

Straightforward chemical arguments lead to the conclusion that
significant amounts of decomposition do not occur at liquid nitrogen
temperatures.  (See Hugh Hixon's article "How Cold Is Cold Enough?"
from *Cryonics* magazine, January, 1985, or fetch cryomsg 0015.)
This isn't true for either dried or embalmed tissue kept at room

Also, Alcor and Trans Time have done experiments with dogs that
demonstrate that part of the suspension process does not cause
damage.  Dogs have been anesthetized, perfused with a blood
substitute, and cooled to slightly above 0 C for several hours.
After rewarming and replacing the original blood, the dogs revived
with no obvious brain damage. Experiments like this cannot be done
with drying or embalming. 

Another option that may become possible in the future is vitrification.

2-11. What is vitrification?

(Next paragraph copied from CRYOMSG 6 posted by Kevin Brown)

The cover article of the Aug. 29, 1987 issue of Science News describes
vitrification, which achieves cooling to a glassy state without the
water crystallizing into ice.  The advantage of this is that the cells
do not suffer the mechanical damage from the crystallization.  The
main disadvantage is that the concentration of cryoprotectants
required to achieve this is toxic.  It is also, currently, a
technically difficult and expensive process requiring computer control
of cooling rates, perfusion, etc.  The March, 1988 issue of Cryonics
magazine ("The Future of Medicine", Part 2 of 2) suggests that
vitrification may not be needed for ordinary organ banking, since
other, cheaper methods may be good enough.  For tissues and cells,
though, it has a lot of promise for the commercial market.  Thus,
commercial research into vitrification may stop short of what is
needed for making it viable for preservation of large organs or whole
bodies required by cryonics.

2-12. How is the baboon? Did it live? Any brain damage?

According to Art Quaife as of 14 Jul 92, the baboon is well and has
no signs of brain damage.

This is part of what CRYOMSG 865 posted by Art Quaife has to say about
the baboon:

Berkeley, California, May 29 1992.  BioTime Inc. has, for the first
time, successfully revived a baboon following a procedure in which
the animal's deep body temperature was lowered to near-freezing and
its blood was replaced with BioTime's patent-pending blood-
substitute solution.

The animal was anesthetized, immersed in ice and cooled to below 2
degrees Celsius, using the BioTime solution with cardiopulmonary
bypass procedures.  After being bloodless and below 10 degrees
Centigrade for 55 minutes, the animal was rewarmed and revived.  The
baboon is presently under study by BioTime scientists to determine any
long-term physical effects.

The company intends to conduct further experiments on primates, using
its blood-substitute solutions.

2-13. Who has successfully kept dogs cold for hours?  Did they survive? Any
      brain damage?

Several people have achieved that.  The first cryonics organization to
do so was Alcor, in the mid 1980's.  For example, the Jan. 1986 issue
of Cryonics magazine describes, in the article "Dixie's Rebirthday", a
German Shepherd dog named Dixie who "experienced the privilege (and
the peril) of having all her blood washed out and replaced with a
synthetic solution and then being cooled to 4 C.  For four hours she
was held at this temperature: stiff, cold, with eyes flattened out,
brain waves stopped, and heart stilled.  Then, she was reperfused with
blood, warmed up and restored to life and health."  She made a total
recovery.  Several variations, with different perfusates and slightly
different temperatures and/or times were also performed by Alcor.
Later, ACS performed a similar experiment on a beagle named Miles and
recently (1992) BioTime successfully cooled and revived a baboon.

In comparison, hypothermic cardiac surgery was pioneered on humans
decades ago, although the temperatures used were not nearly as low as
in the dog experiments above.  More recently, the October 1988 issue
of The Immortalist described successful surgery on a brain aneurysm in
which the patient was cooled to 15 C for almost an hour.  During that
time the patient's blood remained drained from the body, there was no
respiration, the heart did not beat, and the brain barely functioned.

2-14. Who froze the roundworms?  What happened?

(This text is quoted with slight modifications from CRYOMSG 790 posted
by Charles Platt)

Gerry Arthus, Alcor New York's Coordinator, has announced preliminary
results of an experiment which was designed to investigate whether
memories will survive cryonic suspension.

For his experiment, Gerry used Caenorhabditis elegans, a nematode
(tiny worm) that's one of the simplest living creatures. It has a
complete nervous system, however, and can be "trained" in a
rudimentary way. Worms that are raised in a warm environment will
"remember" it and will prefer it if they are given the choice.
Conversely, worms that were raised in a cooler area will tend to
prefer that environment.

Gerry placed a small number of worms in a cryoprotective solution and
froze them to -80 degrees Celsius for two hours.  After he revived the
worms, the ones that survived the experience still "remembered" their
former environmental preferences. So far as we know, this is the
world's first experiment designed to verify that memory is chemically
encoded and will survive the freezing process.

The sample that Gerry used is too small to prove anything
conclusively. Soon, however, Gerry hopes to repeat the experiment with
a larger sample. He also intends to devise tests to eliminate the
possibility that the worms changed physiologically to adapt themselves
to warmer or cooler environments.

2-15. What were the circumstances under which cat brains produced
      normal-looking brain waves after being frozen?

This was reported by I. Suda and A.C. Kito in Nature, 212, 268-270 (1966).
The cat brains were perfused with 15% glycerol and cooled to -20 C
for five days and, upon rewarming and perfusion with fresh blood,
showed normal brain function (as measured by EEG).  Since this experiment
was done so long ago, and technology has improved considerably since
then, there is some interest in redoing these experiments to see how
well we can do now.

The April 1992 Cryonics, volume 13 number 4 page 4, talks more about
this and gives more references. Appendix B of CRFT talks about the
plausibility of repair in general.

2-16. Would it be possible to use some improvement on modern CAT or MRI
      scanners to infer enough about the structure of a brain to reconstruct
      the memories and personality?

This was discussed on the cryonics mailing list some time back.  The
conclusion was that using radiation to infer the structure of the
neurons in a brain in a reasonable amount of time would require enough
radiation to vaporize that brain.  Then the discussion moved on to
nuclear-bomb x-ray holography devices in outer space that record the
results on film that has to be moving by at an astronomical speed so
it doesn't get caught in the blast.  Cremation and immortality, all in
one convenient package.  I find nanotechnology-based approaches more
believable, albeit less spectacular.

To read about this yourself, fetch articles from the cryonet archive
with the words "brain scan" in the subject.  There are 18 as of July
30, 1992.  See the "What is a cryomsg?" question, number 8-2.

2-17. Does background radiation cause significant damage to suspendees?

No.  Ralph Merkle addresses this in in the cryonet archive, message
558.  He estimates that background radiation should not be an issue
for at least 50,000 years of storage.  See question 8-2 for
instructions on how to fetch this.

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