X-Message-Number: 0018.5 Subject: Cryonics FAQ: Part 5 Cryonics Frequently Asked Question List Section 5: Neurosuspension Last Modified Sun Jan 29 15:13:09 1995 (You can fetch cryomsg "n" by sending mail to with the subject line "CRYOMSG n", where "n" is a mesage number. There is more about this in the answer to question 8-2. The index to this FAQ list is cryomsg "0018.1". ) Copyright 1993 by Tim Freeman. See the end of Section 1 for restrictions on redistribution. 5-1. What are the pros and cons of neurosuspension (only freezing the head)? (The next two paragraphs are taken from CRYOMSG 6 posted by Kevin Brown.) An undisputed advantage of the neuro option (over whole body) is cost, both for suspension and for maintenance (liquid nitrogen required to remain frozen). Another advantage is the quality of perfusion with cryoprotectants attained during suspension. Each organ has its own optimal perfusion protocol and when the suspension can concentrate on the head only, the quality of perfusion of the brain does not have to be compromised to attain better perfusion of other parts of the body. Another important advantage of the neuro option is mobility. Whole body suspendees are stored in large, bulky containers that are hard to transport whereas the neuro suspendees are stored in a concrete vault on wheels that can be quickly hauled away in case of fire or other emergency. (Also, if necessary, they can be removed from the large vault and transported in smaller units that fit into a van.) An obvious disadvantage of the neuro option is bad PR; it sounds gruesome. Also, one would think that revival (as a whole, functioning, healthy human being) when only your head was preserved would be more difficult than if your entire body was preserved. However, the whole body situation may not be that much better. Mike Darwin of Alcor noticed several years ago, when examining two suspended people being transferred from another organization to Alcor, that every organ of their bodies suffers cracking from thermal stress during freezing. In particular, the spinal cords suffered several fractures. Thus, the whole bodies were not quite as "whole" as most people assumed. Another reason that a whole body may not offer much more than the head alone is that the technology required to revive people from (whole or neuro) cryonic suspension should also be able to clone bodies, which is much simpler than fixing damaged cells. One possible objection to this approach of recloning a body to attach to the head was voiced by Paul Segal of ACS (in the April 1988 issue of The Immortalist). He suggested that adult cells in the head may be missing some of the DNA needed to reclone the remainder of the body. Even if this objection is valid, it is easy to circumvent by storing samples of all the major organs with the preserved head (which is standard practice at Alcor). If the technology for suspension improves enough to make it possible to store a body without much damage, that might tilt the ideal tradeoff away from neurosuspension if the stored body is easily repairable. See the booklet "Neuropreservation: Advantages and Disadvantages" published by Alcor for a more thorough discussion. 5-2. How many people have chosen neurosuspension over whole-body suspension? (This question has only a partial answer.) The different organizations market neurosuspension differently, so the answer depends on which organization you have in mind. >>>Question sent to on Wed Jul 29 1992<<< As of June 20, 1992, Alcor had 271 suspension members and 22 members in suspension. I don't yet have information about how many of the suspension members have chosen neuropreservation. ACS has six whole bodies, two heads, and two brains in cryonic suspension. They can do neurosuspensions, but they do not promote the option. Art Quaife estimates that less than 20% of the living members of ACS have chosen neuropreservation. The Cryonics Institute does not do neurosuspensions. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=0018.5