X-Message-Number: 4438
Date: 23 May 95 06:21:12 EDT
From: Mike Darwin <>
Subject: Re: preservation of brain tissue

Joe Strout asks about reversible brain cryopreservation as an adjunct to
research in neurophysiology:

> Many researchers have to go through a large number of animals (usually rats or
>mice) when doing experiments on brain slices, because the tissue needs to 
>be alive.  This requires one animal per trial (when trials are done 
>successively).  If we could freeze and revive slices, we could reduce the 
>number of animals needed by a factor of 10 or 100.

This is complex subject beyond the scope of detailed discussion here.  Call me:
(909)987-3883.  The simple answer is that you would FIRST have to sort out the
effects of cryopreservation: cryoprotectant toxicity, cryoinjury, effect of
bathing media composition (i.e., intracellular solutions vs. the normally used

extracellular ones) and the technically demanding and costly procedures required
to introduce cryoprotectant, cryopreserve and store the sample, thaw the sample

under acceptable conditions, and remove the cryoprotectant.  This ain't easy and
it ain't cheap, even for slices.  Rat brains are particularly refractory to
introduction of cryoprotectant.

Rats are cheap: think about the cost of the above, not including the vast number
of studies which would be needed to rule out the possibility of artifacts from
cryopreservation: in other words will cryopreserved slices behave
histochemically, neurophysiologically, and appear ultrastructurally the same as
those from a fresh animal?  Each investigator would have to establish this for
his/her model.  That adds up to a lot extra dead rats and $$$.

Mike Darwin

Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=4438