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