X-Message-Number: 3462
From:  (Thomas Donaldson)
Subject: SCI.CRYONICS: re various postings #3300 to #3310
Date: Sat, 10 Dec 1994 21:20:35 -0800 (PST)

Hi again!

1. About working out the connectivity of our brains in detail:

Yes, this would be extremely useful. In the spirit of trying to use methods
closer to the present, we might consider extensions of the biological stains 
already used. Presently these stains will simply stain some particular 
structure passively. We might think of using a system of (adapted/created)
viruses as stains instead... or even larger microorganisms. These would
respond by staining only when particular chemicals reached them. We might even
be able to get them to respond by forming small antennae. These would allow use
of MRI to NONDESTRUCTIVELY recover connections.

One reason for stains is that they can show a structure which otherwise might
not be visible except under much higher magnification. It's also important to
such an attempt to understand that we need not mark every nerve connection 
at once. We might instead work out connectivity in phases: first one set of
nerves, then those connected to them, then the neurons connected to these,
etc. (Imagine our "staining bacteria" to be passing from one neuron to those
which synapse upon it).

These ideas are intended only as initial ones, and clearly would need further
development. Since we already know that brain cells in some birds contain 
particles of magnetic substance, bacteria with such particles aren't so far
out of possibility --- especially since genetic engineering techniques more
advanced than our present ones might move the necessary genes from these
birds into the bacteria. Herpes viruses move up through our nerves already,
hence provide a system for tracing nerve connections already, and one that 
could be used in these "staining bacteria". In fact, this trait of herpes
has already been used in a small way to work out nerve connections, but it
would clearly need more development.

2. The notion that quantum mechanics has anything at all to say to someone
interested in consciousness is absurd. Our brain does not operate on that
scale. For anyone who doubts this, a bit of neurobiology may help: try
(for starters) Churchland's NEUROPHILOSOPHY, or Levitan and Kaczmark THE
NEURON. Yes, some respected people have raised this possibility. I am sorry
to say that by doing so they simply show their ignorance --- and since books
on neurons and brains are easy to find and easy to read, that ignorance 
unfortunately is willful rather than innocent. Churchland's book has a 
good introduction to neurobiology, and discusses philosophical questions
such as identity on that basis.

			Long long life,

			  Thomas Donaldson

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