X-Message-Number: 0025.1
Subject: Suda's Cat Brain Experiment & Conservatism in Science

              Isamu Suda's Cat Brain Experiment
                 and Conservatism in Science
                       by Charles Platt

  (The following text is from a book about cryonics that is
   still in preparation. Copyright 1993 by Charles Platt.)

     In the mid-1960s, at Kobe University School of Medicine,
in Japan, a scientist named Isamu Suda was thinking about the
concept of freezing and restoring life. Suda knew of Audrey
Smith's work in England, freezing and attempting to revive
hamsters. He decided to adopt a different strategy.
     Suda wanted to find out whether the brain of a mammal
would still function after a period of freezing, and he
devised an experiment which would be a first step in that
direction. His method was simple, although some readers may
find it distressing. He gave a cat a general anesthetic,
slowly reduced the temperature, and circulated artificial
blood to protect the cells from damage. Then he removed the
brain and perfused it with a solution of 15 percent glycerol,
so that the cryoprotectant reached every cell. Finally, he
froze the brain to a temperature slightly below zero degrees
     A month and a half later, he warmed the brain, flowed
more blood substitute through it, and attached a standard
electroencephalograph (EEG). The results were astonishing.
Suda's equipment picked up brainwaves, and they looked very
much like records which he had taken while the cat was still
     He repeated his experiment many times. Some cat brains
were put in cold storage for seven months, but they still
produced brainwaves when they were revived--though the traces
weren't so clearly defined.
     In 1966, Suda wrote up his results and managed to get
them published in Nature, probably the most conservative,
prestigious scientific journal in the world. But he didn't
stop there. He kept some brains frozen for seven years. When
he finally thawed them, even they still showed some activity.
He wrote another paper and reported "spontaneous discharges"
of cells in the cerebellar culmen, and "rhythmic but
continuing uniform wavelets."
     This research may seem unsettling, not just because it
involved experimental animals, but because of the
implications it raises. How can a disembodied brain that has
been frozen and thawed be truly "alive"? If its cells have
been protected from damage so that they start functioning
again, does that mean the brain is now "conscious"? Does it
have thoughts and feelings?
     Today, we are no closer to answering those questions
that Isamu Suda was in 1966. Suda's research was provocative,
and its results were amazing; but in the decades since then,
no one has taken it any further.

     Scientific research is a process of building one
discovery on top of another, in a search for truth.
     That's the idealized view. In real life, scientists
journey through science like explorers opening up a seemingly
endless continent; and like explorers, they have very human
needs and fears. They need recognition and funding. They fear
being left in the wilderness.
     When someone blunders boldly into a new, fertile area,
other scientists tend to flock toward it, eager to share in
the wealth and the glory. By contrast, in areas where the
terrain is difficult or the soil seems thin, scientists tend
to drift away, looking for a better row to hoe.
     Taking this analogy further, there are some areas of
science where the terrain is not just difficult but has been
polluted. These areas are pseudoscience--topics such as
extrasensory perception or UFOs, tainted by the whiff of
sensationalism and fakery. For the sake of their professional
health, most scientists feel an instinctive need to stay as
far away from these toxic areas as possible.
     This is truer for some scientists than others.
Cosmologists, for instance, seem happy to explore wacky ideas
without worrying about the consequences. Fred Hoyle, one of
the most famous cosmologists of all, once claimed that
seasonal viruses come to Earth from outer space. A lot of
people argued with him, but because of his speciality, no one
thought any less of him for being a bit eccentric.
     Biologists are a different breed. They seldom indulge in
wild theory; they spend their lives working within the
practical limits of cells and tissue, taking small steps
based on slow, careful study. Anyone in their field who tries
to be bolder than that is liable to seem "unscientific."
     Isamu Suda's experiment raised some challenging
implications--but maybe they were a little too challenging.
The experiment itself seemed almost like a stunt. It didn't
actually prove anything; it was properly documented and
controlled, but it had the smell of pseudoscience, like
something out of The National Enquirer.
     Perhaps this is one reason why no laboratory in the
world picked up where Isamu Suda left off. No other biologist
repeated his work to verify it, and no one tried adjusting
the variables to get better results.
     In fact the whole field of cryobiology has become
extremely cautious since the 1960s. These days, at the annual
conferenced sponsored by the Society for Cryobiology, you
will find no trace of the bold work that was done three
decades ago. Instead, you will hear rather dull, dry papers
on topics such as how to freeze ears of corn without damaging
the proteins.
     Nonconformists like Audrey Smith hardly exist anymore.
Instead, there are men such as the editor of Cryobiology
Letters, who became so interested in the subject of plain,
ordinary water, he wrote an entire five-volume treatise on
     This is a long way from the ambition to freeze and
restore animal life. Perhaps the retreat was inevitable, as
the implications became more disconcerting. But it is also
worth noting that the cautiousness of cryobiologists
intensified as cryonics became a popular concept. Cryonics,
after all, tended to attract people without scientific
credentials who talked openly about achieving immortality. It
sounded like pseudoscience, and at first, in some respects,
it was--simply because the cryonics practitioners lacked the
resources and the training to do the job properly.
     Today, at the Alcor Foundation, sophisticated medical
procedures are used in a fully equipped operating room, and a
contract surgeon performs the open-heart surgery which is
needed to perfuse patients properly with cryoprotectants
("anti-freeze" designed to reduce the cell damage that would
otherwise occur when the patient is cooled in liquid
     Also, privately funded research has picked up where the
cryobiologists left off, and is yielding new data which we
hope will result in better perfusates and suspension
     One day, we believe that cryonics will prove itself as a
bona-fide procedure, at which point the rift between cryonics
and the scientific community may be healed.

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