X-Message-Number: 7497 From: (Thomas Donaldson) Subject: Re: CryoNet #7441 - #7453 Date: Mon, 13 Jan 1997 14:31:53 -0800 (PST) Hi again! Thanks to M. Darwin for allowing upload of part of the manual he wrote, and thanks to S. Harris for the upload. Useful and interesting. As for the ideas in the book SHUFFLEBRAIN, quite simply put, they are now long outmoded. Neuroscientists now have a much better understanding of memory. A reasonably popular, brief discussion in book form is Steven Rose, THE MAKING OF MEMORY: FROM MOLECULES TO MIND. But SHUFFLEBRAIN does describe some VERY interesting experiments which deserve to be thought about (and expanded upon). Apparently the brains of these salamanders were actually able to put themselves together again, given the necessary environment and time... without any other intervention. We know now that several different chemicals inhibit repair in mammalian (humans are mammals!) brains, and the basic processes for repair can be produced once those chemicals are prevented from acting. We're nowhere near being able to cause as much brain repair as the salamanders, but the possibility exists that we might get there. This will take lots of research: further exploration of the abilities of salamanders (just how well was their memory preserved through this damage and its repair? What are the limits to their repair abilities) and in mammalian brains (current means to inhibit the biochemicals preventing repair are far from the best imaginable. What can be done to help this process?). While other problems certainly exist in suspended, brain damaged patients, and every one of these needs addressing, we will be a bit further along in solving them if we had even the barest understanding of how we might effectively promote repair in a brain sliced into pieces (note that autopsy does exactly that --- not that we could consider the problem of reviving autopsied patients in any way solved just with this understanding). I will finally add that (IF the damage due to unprotected freezing can be dealt with --- hardly a trivial point!) then I'd expect far better preservation of memory in a brain sliced into relatively few pieces than in one which was totally disarranged and mixed up. The best current theory of long term memory suggests that we grow new and stronger connections between our neurons whenever we learn. Slicing a brain into a few smaller pieces disrupts that much less than mixing it up into many small pieces. Best wishes, and long long life, Thomas Donaldson Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=7497