X-Message-Number: 4396 From: (Thomas Donaldson) Subject: results of brain transplants Date: Sat, 13 May 1995 10:55:43 -0700 (PDT) The place to find a full account of these experiments is one you might find difficult to find (find find find). It is a book, now out of print, by a fellow by the name of Paul Pietsch and titled SHUFFLEBRAIN. Pietsch's ideas about how memory works are now long out of date: he had the idea that our brains somehow worked like holograms. However the EXPERIMENTS described, some by Pietsch and many by other scientists, still ask us to think about what is going on. And it also has references so that if you wish to search them all out but can't find the book itself, you will still be able to get the essential information, without Pietsch's theory, too. The bibliography is 6 pages; if you get really interested I will send you a photocopy of it by mail (I'd need your address!). I will say that many of the titles probably don't pertain directly (it is a bookrather than a paper) and I will give some of those which touch the subject most closely: CJ Herrick THE BRAIN OF THE TIGER SALAMANDER, U of Chicago Press, 1948 Herschkowitz, M; Segal, M; Samuel D "The acquisition of dark avoidance by transplantation of the forebrain of trained newts (Pleurodeles waltl)", BRAIN RESEARCH 48(1972) 366-369 Pietsch, P; Schneider, CW "Brain transplantation in salamanders: an approach to memory transfer" BRAIN RESEARCH 14(1969) 707-715 Schneider, CW "Avoidance learning and the response tendencies of the larval salamander Ambystoma punctatum to photic stimulation", ANIMAL BEHAVIOR 16(1968) 492-495. Unfortunately some of the work he describes in the book (on brain transplants between salamanders and between species) isn't in the papers. It can be found in the book from pp. 90 to 171. The frog to salamander experiment was actually (sorry!) from tadpoles to salamanders, and did lead to animals which did not behave as normal salamanders. There is nothing in his book about specific tests of MEMORY rather than instinctive behavior (inborn neural circuits) in that particular experiment. At one time I had a nice conversation with Greg Fahy about these results, which (I think) beg both to be duplicated and extended. One of the major practical problems in doing either one is that these animals (salamanders) aren't nearly so easy to work with as rats or mice. And duplicating the experiments would require using the exact species of salamander used by these scientists, which makes it even harder. It would still be very informative to look at these results again, since they may say something important both about memory and brain connectivity. As I have mentioned before, neurophysiologists have been moving over to the idea that special chemical factors in our brains PREVENT regeneration rather than that the ability to regenerate is absent entirely. If that is so, then these experiments may say something significant about how our memories work, too. Long long life, Thomas Donaldson Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=4396