X-Message-Number: 16225
Date: Mon, 7 May 2001 11:10:19 -0400
From: Thomas Donaldson <>
Subject: CryoNet #16213 - #16220

Hi again!

About stem cells: they have been studied now, with significant progress,
for several years. We may yet see their use in repair.

However the major issue for cryonicists isn't the repair of organs,
or even the repair of SOME brain regions, but the repair and recovery
of memory in our brains. Even worse, for some time neuroscientists
have generally believed that our memories were stored in the connections
(at a low level) of our neurons.

Although this work has hardly received the interest that work on stem
cells has, there are two strains of research which may show that this
common theory has some big holes. Just how we'll fix those holes remains
unknown, but they are certainly present and need attention.

First, we grow new neurons even as adults, and these neurons seem to
play a role in learning, too. The next-to-latest issue of PERIASTRON
talked about this issue in more detail. Note that if neurons grow and
disappear, especially in the brains of apes (of which we are one) then
we can't just say memory is a matter of connections. There must be
additional factors here. Second, connections between neurons at the
lowest level (synapses) seem not to be nearly as constant as people
once thought. Every time neuroscientists have been able to watch this
in action, they've found synapses coming into existence and going out
of existence over time. (There ARE hard experimental problems here
to doing this, but the stability of synapses does not look very great).
Since synapses form the main connections between neurons, their 
stability or lack of it must tell us something important about 

Just some scientific comments about how stem cells relate to cryonics.
Yes, we'd like to repair our bodies too, but if we cannot recover our
memories we are no better than twins born at a different time (what
many want to call "clones").

			Best wishes and long long life for all,

				Thomas Donaldson

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