X-Message-Number: 4742
Date: Tue, 8 Aug 1995 12:03:39 -0700 (PDT)
From: Joseph Strout <>
Subject: fixation + freezing?

Yesterday it was mentioned that chemical fixation, while crude, may in 
fact save enough information for an eventual recovery.  It was also 
pointed out that while the initial costs might be high, the result is a 
maintenance-free patient who could "survive" about as well in a coffin as 
in a caretaking facility.

Now, I'm personally much more comfortable with being safely in a LN dewar 
-- but could the two approaches be combined, to provide a safety net?  
Severe chemical fixation followed by freezing would be just as stable in 
the dewar as freezing without fixation -- but in the event that the LN 
stops flowing some day, the result would be a room-temperature fixed 
brain, rather than a room-temperature rotting one.

Of course, this would take very high concentrations of fixative; I saw 
fixed human brains begin to deteriorate over the course of a few months.  
It may be that no fixation can preserve anything but mush over the course 
of decades.

Even if sufficient fix could be achieved, it might interfere with the 
cryoprotectant, either by chemically disabling it in some way, or 
physically preventing it from reaching the finer blood vessels.

And even if THAT's not a problem, we are certainly adding insult to 
injury by heaping poisonous fixatives on top of freezing/thawing damage.  
Such treatment might delay the patient's recovery, even if the LN keeps 
flowing steadily.

So, having outlined the idea and all the objections I can think of, I 
wonder what you all think about it?

,------------------------------------------------------------------.
|    Joseph J. Strout           Department of Neuroscience, UCSD   |
|               http://sdcc3.ucsd.edu/~jstrout/    |
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