X-Message-Number: 6347
From:  (Thomas Donaldson)
Subject: Re: salamander memory
Date: Fri, 14 Jun 1996 12:50:14 -0700 (PDT)

Hi again!

Perhaps I should be more specific about the experiment --- and come down to the
name of the person involved. If he's on the net he knows who he is; right now
I won't discuss the name. The initials are G.A.

But here's a bit more about the experiment, and some history. Some time ago,
Paul Pietsch wrote a book, SHUFFLE BRAIN, in which he described an experiment
(either repeated by him or done entirely by others) in which members of one
species of salamander (Ambystoma punctatum) would not only survive but 
remember after their brains had been taken out and the pieces put in again
out of order. Pietsch describes other experiments, including transplanting 
a frog's brain into a salamander (which had had its own brain removed). 

There are difficulties with this experiment, and I don't want to minimize
them. Moreover, Pietsch's book is marred by a theory about memory which few
people believed then and even fewer people believe now (at the time he 
wrote it, neural nets had not become prominent, so he had devised a different
theory which --- so I understand --- most neuroscientists now would think
to be totally out of the question). The real interest is in the experiments
themselves. (Unlike mammals, salamanders retain considerable abilities to 
repair their brains after injuries which would simply kill a person).

As I understood the planned experiments, an attempt would be made to freeze
these salamanders, or their brains, and then implant the thawed brains in
another salamander. Since salamanders are hardly known for LARGE brains, 
it would also be (relatively) easy to infuse glycerol or other cryoprotectant
into them. 

One of the major problems that turned up was that of simply getting enough
salamanders. Mice are easily obtained from lab supply stores, salamanders
are not. And if we wish to really duplicate the experiments of Pietsch and
others, we'd have to get not some general salamander but Amblystoma punctatum,
which increases the difficulty of getting them by an order of magnitude.

And I don't know just what happened --- though I would very much like to find
out. I mean that even if the experiment failed because GA couldn't get enough
salamanders. 

So that is the salamander experiment. And if GA is listening, I'd like to
hear from him --- even if the experiment was a crashing failure. These ideas
have left a very large question mark ???? in my own mind, especially now that
neuroscientists have begun to see that we too have repair capabilities, which
are frustrated, rather than no repair abilities at all. And I believe we
can even explain them in accord with current theories --- but I would not 
explain any experiments which did not exist.

			Best and long long life,

				Thomas Donaldson


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