X-Message-Number: 25961
Date: Sat, 2 Apr 2005 08:42:34 -0500
From: Thomas Donaldson <>
Subject: To B Coetzee

Your notice of the NATURE NEUROSCIENCE article is good. I'll look
at it myself.

However I'll stick my neck out and suggest that you may have 
misunderstood one thing the article was saying/proposing. Two 
areas in our brain produce stem cells: our dentate gyrus, in our
hippocampus, and a layer of cells surrounding the brain ventricles 
(areas filled with a fluid close to spinal fluid). When another
brain area needs new neurons, stem cells (sometimes) migrate
there, becoming neurons as they move. CPG15 may help damaged areas
call for new stem cells to migrate to them.

In many animals, but (surprise!) not in humans, stem cells from
the ventricular layer migrate continuously to those parts of the
cortex dealing with smells. Even in the case of these animals,
some researchers have found or claim to have found neural stem
cells migrating to other centers too, although not so many. The
implication of this observation is that those stem cells will
end up doing something other than smelling. So far as I know,
no one strictly speaking knows where the human stem cells from
the ventricular layer may be going, but the implication is that
they're going to help activity in other brain areas. 

T here is a strong implication too that the new neurons which 
result form new circuits and thus play an important role in 
memory itself --- not the brief kind but the longterm kind. This
is a subject of experiments going on right now, and a report
of such work gets into PERIASTRON, too.

         Best wishes and long long life to all,

            Thomas Donaldson

Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=25961