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/ | `------------------------------------------------------------------' Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=4742