Untitled

Chapter 6
Cryonic Life Extension: Scientific
Possibility or Stupid Pipe Dream?
I’ve long thought it a pity that non-transhumanists equate trying
to conquer death with a childish fear of death and a lack of
wisdom. This is like saying Sir Edmund Hillary had a childish
fear of mountains.
Philip Goetz.
Abstract This chapter is concerned with cryonics and suspended animation. Like
the previous chapter, it contributes substantially to the philosophical debate on where
the line between life and death should be drawn. The ultimate aim of cryonics is
to achieve nondestructive freezing (cryopreservation) of advanced organisms like
humans so that they can be safely thawed in the future, usually with a view to
obtaining advanced medical treatment not currently available. In this chapter number
of scientific and philosophical questions presented by cryonics are discussed, such
as whether cryonics is real science or simply a waste of money, the legal and moral
status of cryonically suspended individuals, and how to deal with the possibility
that the thawed individual might end up with some organs working but with severe
neurological impairment.
6.1 Introduction
In previous chapters we examined a variety of issues lying at the intersection of tran-
shumanism and ethics: genetic enhancement, neuro-enhancement, human enhance-
ment through the use of drugs, animal-human hybrids, and computer-human hybrids.
Also explored were the moral, ethical and legal problems associated with brain death
in both its complete and incomplete forms. It was argued that the notions of person-
hood and personal identity were central to the discussion.
In this chapter we explore some of the moral, ethical and legal problems asso-
ciated with another process lying at the intersection of transhumanism and ethics:
© Springer Nature Switzerland AG 2018
D. J. Doyle, What Does it Mean to be Human? Life, Death, Personhood
and the Transhumanist Movement, Anticipation Science 3,
https://doi.org/10.1007/978-3-319-94950-5_6
113
114 6 Cryonic Life Extension: Scientific Possibility or Stupid Pipe …
cryonic life extension, the as yet unperfected process of placing patients into a state
of suspended animation using nascent technologies such as “vitrification.” Once
again, the notion of personhood and personal identity can be seen to be central to the
discussion.
6.2 What Is Cryonics?
Important early work in the field of cryonics date back to Ettinger’s seminal work
The Prospect of Immortality (Ettinger 2005a) and his later book Man into Superman:
The Startling Potential of Human Evolution (Ettinger 2005b). In addition, a volume
entitled The Philosophy of Robert Ettinger (Tandy 2002) describes the considerable
impact that Ettinger had on influencing the nascent field of cryonic preservation.
The central scientific quest in cryonics is to develop, test and validate technology
that would reversibly preserve brain-encoded information essential to personhood
after cryonic preservation. Advocates of cryonics seek to use cryoprotectants, vitrifi-
cation and extreme cold (such as immersion in liquid nitrogen) to extend the life of an
individual who can no longer be sustained for long periods by conventional medical
technology. This cryonic life extension is intended to be employed for decades or
even centuries, until safe reversal of the preservation process as well as treatment for
the underlying medical condition becomes feasible as a result of new developments
in medicine and technology.
Such an undertaking is predicated on three important principles, only one of
which is well-established at this time. The first principle of cryonics is that life can
be stopped or suspended as long as appropriate attention is directed at preserving
the basic biological structures upon which life is based. Although this principle is
well-established for a number of animal species as well as for human embryos (Pegg
2007), much needs to be done to extend the principle to include full human beings.
That being said, this is a field of active research in medical science and it is reasonable
to expect that interesting developments will continue to be unveiled by researchers
in these fields.
A second principle is that the use of cryoprotectants and vitrification will be use-
ful in extending the first principle to larger organisms such as adult human beings.
Progress on this second principle is now occurring at the level of entire organs. One
particularly important scientist in this field is Gregory M. Fahy, who has achieved
successful vitrification and autotransplantation of a rabbit kidney using his (propri-
etary) M22 vitrification solution (Fahy et al. 2009; Fahy and Wowk 2015).
The third and most controversial principle is that post-thawing damage to indi-
vidual cells (especially neurons) might be repaired one molecule at a time using the
emerging sciences of nanotechnology and nanomedicine. However, to the extent that
cryonic preservation might eventually be achieved without damage to cellular struc-
tures, or may be achieved through naturally-occurring biological repair mechanisms,
the advanced molecular repair methods referred to above may not be necessary.
6.2 What Is Cryonics? 115
Additionally, it should be emphasized that—at least in principle—damage to indi-
vidual cells may not always result in loss of the information needed to reconstruct a
viable post-suspension organism. Should advanced methods become available to
reconstruct the entire human organism from information reliably preserved and
subsequently exploited despite the presence of cellular damage following cryonic
suspension, this problem might be expected to vanish. One scenario here would
be to clone an entire new body but with the special proviso that the informa-
tion/identity/memories of the original organism be transferred to the new organism.
In such cases the patient would emerge rejuvenated and “better than well” and without
the lifespan limitations of the original cryopreserved tissue. Yet another possibility,
should mind up-loading and down-loading ever become feasible, is that an individual
become recovered in virtual reality.1 This possibility is discussed in Sect. 6.20.
6.3 Is Cryonics Possible in Principle?
Although so far alien to man, the ability to endure winter freezing has developed in
several species of frogs and turtles as well as in a number of species of insects and
microorganisms. This suggests that with appropriate scientific advances reversible
freezing of larger organisms might be possible in principle.
The evidence that reversible freezing of humans may eventually be possible comes
from several sources. First, there is support from nature. For instance, the wood frog
Rana sylvatica utilizes naturally-occurring cryoprotectants in order to survive low
temperatures during winter months. This natural process utilizes glucose, derived
from hepatic glycogen, as well as urea, as cryoprotectants (Costanzo and Lee 2005;
Costanzo and Lee 2008; Muir et al. 2007; Storey et al. 1996). As a result, these frogs
can “endure freezing for at least 2 weeks with no breathing, no heart beat or blood
circulation, and with up to 65% of their total body water as ice” (Storey et al. 1996).
The spring peeper (Pseudacris crucifer) and the gray tree frog (Hyla versicolor) are
other species that can withstand freezing temperatures during winter (McNally et al.
2003).
In recent years, the application of gene screening technology to animals that
tolerate freezing has allowed scientists to identify proteins that contribute to freeze
116 6 Cryonic Life Extension: Scientific Possibility or Stupid Pipe …
tolerance in animals (Storey 2004; Storey et al. 1996; McNally et al. 2003). These
proteins are in turn coded for by genes (DNA sequences) such as fr10, li16, and fr47
(McNally et al. 2003). As our scientific understanding of these processes improves
over time, it is interesting to speculate as to whether it might be possible to use
genetic engineering means to add these genes to the human genome (if they do not
already exist), or to activate them should they be present in the human genome but
not expressed.
The idea would be that should a patient be diagnosed with an untreatable terminal
illness, genetic engineering interventions aimed at inducing natural cryoprotection
might be expected to be more effective than the methods currently in use. Another
possibility would be to create new babies with the required cryoprotectant genes as
a risk mitigation measure against dying from accidental hypothermia in cold climate
regions like northern Canada.
Although this all might seem quite outlandish, consider that as of this writing
(2018) the structure of DNA has been known only six decades. Consider also that it
took only seven decades for humankind to progress from the first powered flight by
the Wright brothers (1903) to the first manned moon landing in 1969.
A second line of argument that the safe freezing of humans may eventually be
possible stems from the fact that human spermatozoa, oocytes and even embryos are
already routinely frozen in in vitro fertilization clinics around the world. Indeed, a
great many individuals alive today were at one time cryopreserved embryos. In fact,
two embryo cryopreservation methods are in common clinical use: slow freezing and
vitrification (Kattera and Chen 2006; Loutradi et al. 2008; Kolibianakis et al. 2009).
6.4 Vitrification
Vitrification is the technology that advocates of cryonic suspension hold as having the
most promise for eventual success. In vitrification, cellular water is largely replaced
by one or more cryoprotectants. In addition, rapid cooling is carried out so that any
remaining water is transformed directly from its liquid phase to a glassy, vitrified
state that occurs with minimal formation of damaging ice crystals.
This process involves a number of special challenges. First, there are biological
limitations to the degree to which cryoprotectant chemicals will be tolerated by cells
undergoing vitrification. Second, while vitrification of cell clusters has been achieved,
it is much harder to do this with an entire organ or an entire organism. Finally, the
required cooling rates can be a challenge. For instance, for embryo vitrification,
cooling rates between 15,000 and 30,000 °C/min are often used (García-Velasco and
Pellicer 2007 ).2 Despite these challenges, as noted earlier, the successful vitrification
6.4 Vitrification 117
and subsequent transplantation of a rabbit kidney by Fady (Fahy et al. 2009; Fahy
and Wowk 2015) suggests that eventual success is mostly a matter of effort, money
and imagination.
6.5 Substrate Preservation Versus Information
Preservation
In dealing with cryonics, it is helpful to distinguish between the information preserved
in a person’s brain and the substrate used to hold that information. The information
that makes us a person includes our longitudinal memories, as well as our hopes,
our dreams and countless other mental events. As we discussed in Sect. 3.3, this
information is unique to us—it is what makes us persons. How exactly this infor-
mation is encoded into the brain substrate is a field of active neurologic research.
The reader interested in this complex question might start by looking at some of the
articles published in the academic journal Learning and Memory.3 For individuals
who would like a brief sketch on this matter, the following commentary is offered.
One popular theory of how memory is encoded in the brain is based on a hip-
pocampal synaptic plasticity model (Bliss and Collingridge 1993; Shapiro 2001;
Dudai 2004; Conner et al. 2009). The support for this theory comes from a number
of sources. First, in Alzheimer’s disease the hippocampus is one of the earliest brain
structures to suffer damage. That memory problems appear among the first clinical
findings in Alzheimer’s disease suggests that the hippocampus has an important role
in memory formation.
Second, lesions of the hippocampus in humans may prevent the acquisition of
new memories, as in the well-known case of HM. In 1953, a man known as HM
lost substantial portions of his hippocampus, parahippocampal gyrus, amygdala and
anterolateral temporal cortex in a neurosurgical procedure aimed at stopping his
intractable epileptic seizures. While the surgery was successful in eradicating the
seizures, HM ended up with complete anterograde amnesia, although his working
memory and procedural memory remained intact.
Third, hippocampal synapses are known to have “activity-dependent synaptic
plasticity” that provides neuronal level evidence of a possible role in memory. In
2For vitrification on the human-scale, thermal mass and heat conduction properties conspire to
limit the rate of cooling, with the consequence that novel approaches to vitrification must be
sought. Recognizing that there is non-covalent competitive binding of water molecules between
the biomolecules (which incorporate water as an integral component of their structure), the various
components of the cryoprotectant, and crystalline ice, may be the basis for future developments.
Note that the goal of cryoprotection is to avoid irreversible alteration of biomolecular structures,
which ice does by competitive dehydration; the affinity of the water molecules for the ice is greater
than for the biomolecules. (I am indebted to High Hixon, an Alcor Research Fellow, for making
this point during our private correspondence.)
3Information about the journal is available at http://learnmem.cshlp.org.
118 6 Cryonic Life Extension: Scientific Possibility or Stupid Pipe …
this arena, a particularly attractive family of molecular candidates for modulating
synaptic plasticity during learning and memory processes are neurotrophins (NTs).
Finally, the importance of the hippocampus to neuroscience in general and mem-
ory research in particular is evidenced by the fact that there is a journal devoted
specifically to it (called, appropriately, Hippocampus).4
A computer analogy may be helpful in explaining this distinction between the
information preserved in a person’s brain and the substrate used to hold that infor-
mation. In order for a computer to be useful its hard drive (or equivalent memory)
must be loaded with a number of kinds of information. For example, the hard drive
will contain an operating system, as well as a number of applications (word pro-
cessing, spreadsheets etc.), as well as a number of data files (such as the text file
containing these very words). For the computer to be useful, it must contain both
the hardware as well as the information that constitutes its “identity” (programs and
data). If the computer is destroyed, for example by fire, mere replacement of the
hardware would be insufficient to restore the computer to its previously useful state.
Instead, all the information that was unique to that computer would have to be added
as well.
In the world of computers, restoring this information is a relatively simple task
using backup programs that are commonly available. In the case of the brain, there
is as yet no way to achieve this task. In the realm of science fiction brain backups are
done using methods whereby the state of the brain is measured in sufficient detail
that it can be reconstructed on demand. In this sense, there is a rough analogy to
teleportation, another popular science fiction theme.
The importance of this distinction between the substrate and the information
encoded on the substrate is that it could turn out that cryonic brain preservation ends
up preserving brain tissue (substrate) but might still not be sufficient to preserve the
information the brain retains.
6.6 The Two Usual Cryonics Scenarios
In the USA, Alcor, a facility located in Scottsdale, Arizona, is one of several compa-
nies offering a cryonic suspension service. (Although other cryonics organizations
exist, their services, policies, and clinical approaches are similar.5) Candidate patients
carry an alert bracelet requesting that as soon as possible after death, a large dose
of heparin (an anticoagulant) be given intravenously and the newly “dead” patient
be placed on cardio-pulmonary bypass to allow continuing organ perfusion prior to
freezing.
4Information about the journal is available at http://www.wiley.com/WileyCDA/WileyTitle/produ
ctCd-HIPO.html.
5A listing of various services is available at http://www.benbest.com/cryonics/CryoFAQ.html#_V
II__.
6.6 The Two Usual Cryonics Scenarios 119
Two options are offered: a whole-body option (cost: $200,000 and up) and a less
expensive option where only the head is cryonically suspended (cost: $80,000 and
up). In either case the hope is that at some future time the body (or head) will be
able to be unthawed and repaired, although in the case of the head only option, the
problem of finding a matching body exists unless: (1) a new body can be constructed
(perhaps via a variant of cloning or by advanced tissue engineering methods), or if (2)
the newly reanimated head is configured to exist as an isolated perfused preparation
(vide infra), or (3) the head’s information contents are transferred to an entirely new
biological entity (again, perhaps constructed via a variant of cloning), or (4) somehow
a new organism is made to exist entirely in silico.
6.7 Living as an Isolated Head
In the situation where only the head would be preserved, one can imagine three
possible outcomes: (1) failure to successfully reanimate the individual in question
(certainly a possibility, at least in the early experimental phases of any cryonics
research), (2) existence as a conscious, reanimated head attached to a new body (a
situation with numerous challenges beyond mere successful thawing of the head),
and (3) existence as a conscious, reanimated head existing independently from a
body via an artificial cardio-pulmonary-renal-endocrine support system.6
About 50 years ago, White et al. were able to isolate a series of five monkey brains
by surgically removing all anatomical structures surrounding each brain except a
small basal plate of bone and the central portion of the skull (White et al. 1963,
1964, 1965, 1996). These brains were completely isolated from the donor monkey’s
body neurogenically and vascularly, and were perfused in vitro for 30–180 min via
extracorporeal circulation using an immunologically compatible second monkey.
That the isolated perfused brain remained alive and working in this setting was
demonstrated by showing persistent electro-encephalographic activity at the cortex
as well as by showing that the brain was appropriately extracting oxygen from its
blood supply (by obtaining expected differences in oxygen content between the blood
entering the brain and the blood leaving it).
A year later White’s team successfully repeated the experiments using a mechan-
ical extracorporeal system (instead of using the body of another monkey as a life-
support system for the isolated monkey brain). In addition, White’s team was able
to transplant the head of one monkey onto the body of another. The procedure was a
success to the extent that the transplanted head was able to smell, taste, hear, and see,
6Although this last possibility—that of a conscious human existence somewhat like the “brain in a
vat” scenario so often discussed in introductory philosophy courses - seems to be almost ludicrous,
the situation may be technically possible, at least for moderate periods of time. Regardless, it should
be emphasized that the usual “brain in a vat” scenario is a philosophical thought experiment often
employed as an argument for philosophical skepticism and solipsism, and has nothing to do with
cryonics.
120 6 Cryonic Life Extension: Scientific Possibility or Stupid Pipe …
even though the animal was quadriplegic (since the spinal cord was not connected).
The animal even occasionally tried to bite some of the staff.
Of interest, White’s team was not the first to show that conscious existence as a
severed head was possible. Many years earlier, in 1928, Bryukhonenko and Tchetchu-
line at the Institute of Experimental Physiology and Therapy in the USSR showed
that life could be maintained in the isolated head of a dog for a moderate period of
time by connecting the carotid arteries and jugular veins to a system for extracorpo-
real perfusion and oxygenation that used the lungs from a second dog as part of the
setup (Brukhonenko and Tchetchuline 1929a, b; Adamenko 1969). Bryukhonenko
went on to pioneer a number of important clinical developments that lead to the first
Soviet open-heart operation in 1957. For these achievements, Bryukhonenko was
posthumously awarded the Lenin Prize.
Evidence that the isolated perfused dog head was alive and responsive to stimuli
comes from the following New York Times report (Kaempffert 1943):
When the eye was touched it twitched. After twenty minutes there were more signs of life.
The eyes were open by that time and looked alive. The head responded to a whole series
of stimuli. Eyelids blinked when hairs on the brow were plucked. Particularly noticeable
was the response when the mucous membrane of the nose was irritated. In fact, it was often
necessary to hold the head on the plate by force. The muzzle was opened and the teeth were
bared in a snarl. When quinine was placed on the tongue there was every sign of repugnance.
Pieces of sausage were swallowed and ejected through the top of the alimentary canal. In
short, the head behaved just as if it were attached to the body. And in this condition it
remained for about three and a half hours.
A 1940 public domain film “Experiments in the Revival of Organisms” demon-
strating the experiment is available at the Prelinger Archive (http://www.archive.or
g/details/prelinger). The film may also be viewed at http://www.youtube.com/watc
h?v=ap1co5ZZHYE.
6.8 Head Transplantation
In 2013 Dr. Sergio Canavero, director of the Turin Advanced Neuromodulation
Group in Turin, Italy, announced plans to launch a human head transplant program
(Canavero 2015; Canavero and Ren 2016; Li et al. 2017). Given White’s pioneering
work, many of the surgical details related to head transplantation have been worked
out. In addition, White’s work has recently been replicated in China as a means to
further move ahead with head transplantation.7
Still, Canavero and co-workers face two significant obstacles that will have to
be overcome: [1] fusing the donor and recipient spinal cord into a neurologically
integrated unit, and [2] preventing rejection of the graft (an interesting question
arises here—is the graft the body or is it the head?).
7http://www.iflscience.com/health-and-medicine/surgeons-claims-head-transplant-monkey-has-b
een-successfully-carried-out/.
6.8 Head Transplantation 121
Experience in composite graft (e.g., face) transplantation suggests that the
immunological problem, while undoubtably formidable, can likely be overcome,
so getting the recipient and donor spinal cords to fuse meaningfully will be the cen-
tral obstacle to deal with. However, given that polyethylene glycol has been shown
to prompt the growth of spinal cord nerves in animals (Borgens and Shi 2000; Ren
et al. 2017; Kim et al. 2017), this impediment may eventually be manageable as well.
Some proposed technical refinements that extend White’s pioneering work have
been offered by Canavero, the lead scientist/evangelist in the initiative (Canavero
and Ren 2016). First, the recipient’s head and the donor body will undergo thera-
peutic hypothermia to extend the time that the tissues are exposed to any necessary
hypoxic/ischemic insults related to the procedure. Cleanly severing both spinal cords
so as to avoid ragged ends is another key step. Following approximation of the donor
and recipient ends of the spinal cords, implanted electrodes would be used to pro-
vide therapeutic electrical stimulation to the spinal cord (Mondello et al. 2014). Also,
should the application of polyethylene glycol fail to do the job, the use of stem cells
(Tukmachev et al. 2015; Schroeder et al. 2015; Zhao et al. 2015; Li et al. 2014; Ren
et al. 2017) or olfactory ensheathing cells (Tabakow et al. 2014) are two additional
therapeutic approaches that the team is considering.
Of interest, Canavero’s team is not the only group working on this formidable
challenge. A Chinese team (Ren et al. 2014; Ren and Laugel 2013) continue to
work on allo-head and body reconstruction in a murine (mouse) model. Their novel
approach involves “retaining the donor brain stem and transplanting the recipient
head”, an approach that has the advantage of preserving respiratory and circulatory
function. Recently, Canavero has been formally collaborating with Ren and other
Chinese scientists.
Undoubtable, a number of ethical issues are involved in going forward in early
human trials. For example, what should be the role of animal trials before moving
forward to humans? Consider, for instance, item 3 of the Nuremberg Code, which
states that prior animal experimentation be used before moving to human trials: “The
experiment should be so designed and based on the results of animal experimentation
and a knowledge of the natural history of the disease or other problem under study
that the anticipated results will justify the performance of the experiment.”
A completely different ethical issue has been raised by Corlett (2001), although
not in this specific context. He makes the argument that we have a duty to die
inexpensively rather than squander money on a therapy with very limited utility (as
would very possibly be the case with head transplantation). Basically, in a setting
of limited health care resources, argues Corlett, we have a duty to spend the money
only where the impact will have the greatest value.
Let’s end this section with a specific hypothetical scenario. A famous quadriplegic
scientist has developed terminal body failure and, having only months to live, requests
that Dr. Canavero attach his head to the body of an available brain-dead man whose
family is agreeable to donating more than just the customary organs. The scientist
knows the risks as fully as anyone might, and while he is hopeful for the return of
full spinal cord function, quadriplegia is an outcome he can (and does) live with.