X-Message-Number: 17715 Date: Sun, 7 Oct 2001 06:55:18 -0700 (PDT) From: Driven FromThePack <> Subject: Brain damage! I threw in the exclamation mark just for fun! Anyway, great question, William Gale. I'll take a shot at answering it. However, I Am Not A Scientist (IANAS). Well, I guess I am, but I am a *Computer* Scientist. THere are TWO different kinds of brain damage we are talking about here. One is Autolysis. Autolysis is where, after a certain period of time after the brain stops getting oxygen, the brain cells start to self-destruct. Within about 24 hours, that process will have turned the brain to jello. This process is indeed slowed by lower temperatures, just as your refrigerator keeps meat from going bad. I think, also, that this process of brain cell detruction begins fairly soon after "death", but does not have a significant effect for several hours, at least. By the time that 5 or ten minutes of no oxygen to the brain, only a very few of your brain cells will have self-destructed due to autolysis. Not enough to cause "brain damage." That extended period of time after death, i.e., several hours, before autolyssi truly begins to damage the brain, is really why we can do cryonics at all. If autolysis damaged a large fraction of your brain cells right away, cryonics would be useless. But it does not occur right away. I once saw a PhD in neuroanatomy say on a Usenet newsgroup during a cryonics debate that autolysis is the reason why cryonics cannot work, unless cryopreservation begins right away. He was wrong, as far as I know. His name is Terence P. Ma, and you can see that years-old discussion from the Usenet newsgroup sci.med by going to groups.google.com search engine and typing in the relevant words as shown above. However, let me proceed. The brain damage Safer refers to, and the brain damage that paramedics attempt to prevent, is ANOTHER type of brain damage. This is the kind of brain damage that keeps you from being revived after 5 minutes of ischemia (no Oxygen to da brain), and that, if you are indeed revived after 5 minutes of ischemia, might mean that you will have brain damage and be crippled or retarded. This other type of brain damage comes from BEING REVIVED. It does not occur until oxygen flows into the brain upon revival. THis other type of brain damage is due to a cascade of chemcial reactions that occur upon the re-introduction of oxygen to the brain. Certain chemcial reactions take place in the brain while there is no oxygen in the brain; these certain chemcial reactions lay the foundation for the chain cascade reactions to occur when oxygen is re-introduced to the brain ahen being revived. If you could stop that chemcial reactions that occur in that first 5 minutes of no oxygen, you can stop that chemical cascade that occurs upon revival and the re-introduction of oxygen. There is a way to stop those chemical reactions--htye are inhibited by lowering the temperature of the brain by a few degrees. If you drown in cold water, and are dead for 2 hours, and then are pulled from the water and a rCPR is attempted, you will probably be OK. This phenomenon ihas been medically documented. Further, even if a cryonicist "dies" and is not cooled for several hours after "death", this does not mean that all is lost. Yes, if you tried to revive him, you could not, because the cascade chemical reaction will occur when oxygen is reintroduced to the brain through your CPR. However, there is a difference in the type of brain damage caused by the cascade of chemical reactions (CCR), and the type of brain damage caused by Autolysis. Autolysis destroys the cells and thereby destroys the structure of the brain. THat structure carries the information that is *you*. If that is lost, you are lost. Your information will have been *randomized*--after a day or so at room temps, your brain may be jello (no, not Jello brand gelatin, like Bill Cosby eats, but a substance with a Jello-like consistency). I think that the actual time frame varies. It's like meat going bad if you keep it out on the counter. THe cells of the brain are more susceptible to autolysis that other type of cells in the body. So the brain goes first. THe cells in your muscles take longer to autolyze. When my daddy used to kill a deer out in West Texas, he would clean it, and hang it up in a shed outside for a day or so. I asked him why he didn't go ahead and butcher it and put it in the freezer. He told me that he was making the meat more tender. Autolysis at work...THat deer meat was indeed tender after a day or so in the west Texas fall weather, but I bet that deer brain was like...Jello. CCR brain damage does not destroy the structure of the brain. Instead it clogs up ion pathways, or something like that. THat damage makes it impossible for the brain to function properly. That is why there is the five minute limit. But after 5 minutes, even though the brain does not function properly, the STRUCTURE of the brain is still there. Your information--the thing that makes you, YOU--is still there! The brain just needs some repair work. Currently, that type of repair work is beyond the scope of medical science. But there is no reason why we cannot develop the tools to fix CCR brain damage--at some point in the future. Time abides...in the dewar. Someone like Mike Darwin, or Steve Harris, or Hugh Hixon, would be much better qualified to answer this, but since they may not be here, I will stand in. I cannot imagine who "brushed you off" on such an important question. Well, the answer is a bit complicated. Perhaps you can see why cryonics is so little accepted. Not only are there the societal taboos issues, but the technical issues are quite complicated. Heck, even PhD's in neuroanatomy may get confused. BTW, I highly recommend the cryonet archives. All ye may seek regarding cryonics abides within. Good hunting... __________________________________________________ Do You Yahoo!? NEW from Yahoo! GeoCities - quick and easy web site hosting, just $8.95/month. http://geocities.yahoo.com/ps/info1 Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=17715