X-Message-Number: 3568 From: (Thomas Donaldson) Subject: CRYONICS: re #3554 and others Date: Sun, 1 Jan 1995 16:59:59 -0800 (PST) Hi! More on LTP: A good reference for everything that was known up to 1990 is Y. Dudai, THE NEUROBIOLOGY OF MEMORY. You should be able to find it. There has been subsequent work, but that work has not led to any substantial changes. True, if we really wanted to understand memory in a practical way, we'd need to know things that have been found more recently ie. new neurotransmitters, the NO feature that you mentioned, and so on. And if you want to continue your study, the Dudai book is a good place to start. It seems to me very unlikely that older people lose their memory simply because they've run out of space. In the first place, not ALL older people lose their memory. Their number of brain cells remains approximately the same as that of others. So how can it be that only SOME older people, who at least start out with brains the same size and cell number as everyone else's, lose their memory? Their brain cells deteriorate for reasons separate from their memory content. Perhaps I didn't make myself clear, but I've never questioned that our memory capacity is finite. What I was pointing out was that LTP could not alone explain long term memory because if so our memory would be a whole lot less than it is. No one yet, even the very healthiest old person, seems yet to have filled up their memory. I'll also say that this possibility does not worry me when we think about immortality. We don't remember things and ideas we have not used for a long time; I suspect that what will happen will be that older stuff will simply get dumped by more recent stuff. (Besides the likelihood that we'll have ways of adding to our memory, too). Finally, a second matter: I can't fail to notice discussion on Cryonet of lots of alternatives to the present technology for cryonic suspension. These extend from some variation of embalming, to ways of reading out our personalities and memories into a computer, to different ways of improving suspension itself. AS ideas, many of these may have their heart in the right place, but somehow don't really match up with what we know to be true. As an instance, it's not enough to simply suggest flash freezing without providing much more detailed ideas about how it could be done --- even if those ideas required a technology which would take years and billions to develop. Furthermore, I believe that anyone discussing these things needs to keep in mind an ESSENTIAL DISTINCTION. I am not fixed upon using only LN freezing with cryoprotectants for suspension as a PERMANENT solution to the problem. But if we really look at the issue of how to preserve someone as a problem of what we can do NOW, with our present finances, and on a time scale which will not leave most people waiting for its development, suspension using the current methods --- or the kind of modification of them that vitrification would produce --- seems the PRESENT best choice. Anyone who wants to be suspended but refuses to accept present methods may as well forget it. Neither the money, nor the manpower, nor the time, is available to develop anything else --- regardless of its theoretical merits. Even present methods of embalming don't penetrate the entire brain, and therefore won't work for suspension, though they certainly work for cosmetics. I'm in favor of speculation, and believe that it can lead somewhere. No one should be ashamed to speculate nor should they deride others who do. But for many people, those who need suspension NOW, and almost certainly those who will need it in the next 50 years, we should think of the practical issues too. And on that level, I don't know of anyone who is serious enough to actually make arrangements for their own suspension who believes that these other possibilities are accessible. And for those who have NOT made such arrangements I ALSO know of no one who has done more than TALK about those other possibilities. And we all know that if talk were the only thing needed, then we'd be immortal already. Best and long long life, and a Happy New Year, Thomas Donaldson Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=3568