Forget the Body and Just Save the Brain
What gives us the ability to desire a control over aging is our brain. It's the only organ that cannot be, theoretically -- because there are organs that technically can't be --, replaced, our brain is us. The preservation of our brain is all that matters, I can replace my heart, kidneys, or any other organs -- within the limits of technology -- but I can't replace the brain or I will no longer be I -- check out my individuality article. That's why in cryonics people have the option to preserve only the head and brain death is the best definition of death in medicine. Our priority should then be set to avoid aging in the brain; avoiding aging in the rest of the body is secondary unless, of course, it is a necessary action for the upkeep of the brain.
An important question is
whether aging is caused by factors that don't have their origin in
the brain. Perhaps our brain just ages because the other organs in the
body can no longer support it.
If we could change the body at regular intervals to keep it always young,
it might happen that our brain would never age. It's technically
not that difficult, we might soon be able to transplant entire bodies --
although we will probably be paralyzed from the head down, despite some
recent progresses in neuroregeneration that I mention elsewhere. It has
already been tried -- by Dr. Robert White -- in animals -- in a dog and
in monkeys -- to separate the head from the body and then insert the head
in a new body. Notice the fact that I call it body transplants and not
brain or head transplants because size doesn't matter here, for me the
brain is us, and can never be changed, but the body can, and therefore
it's the body that is transplanted. This is still very difficult and expensive,
even if we would follow a path of replacing the most vital systems with
the new techniques of artificially generating organs, it would be very
difficult and even dangerous -- surgeries are always dangerous. Besides,
we would have to use clones of ourselves in order to avoid a whole range
of incompatibilities that could impose damage on the brain. This would
be extremely hard and expensive even with new technologies. Perhaps is
worth a try with animals, we might learn something out of it. Nevertheless,
I think that even if this could be made without damage to the brain, we
would still age, perhaps slower, but we would still age.
The reason is
that, like I mention in Why Are We Allowed to Age?, aging is a result of
mistakes in our genotype that evolution hasn't found yet necessary to correct,
it is logical that this mistakes also exist in brain. Take the Creutzfeldt-Jacob
disease -- or human variant of the mad cow disease. It is caused by a defecting
protein -- called a prion -- that usually only acts decades after being
produced or absorbed. Aging is probably a result of many proteins and other
molecular pathologies that act, or stop acting, at different times and
with different extensions -- this is quite arguable and I discuss it in
another article. It is logical to think that these proteins also exist
in the brain and that aging will also appear in it -- remember that the
genes are the same for all our cells.
Short-term memory loss, personality and cognitive changes with age, dementia,
decline of the nervous system and senses, and many other changes are likely
to occur with aging. The main cause of this is the loss of neurons. This
loss is still quite mysterious because, until recently, neurons were not
thought to be able to divide -- they were considered postmitotic cells.
Dr. Elizabeth Gould and Dr. Bruce S. McEwen -- together with their colleagues
-- showed recently that neurons can replicate in adult monkeys. This was
observed in an area of the brain called hippocampus, which is used for
long-term memory.
Scientists think that this incredible
discovery should also apply to humans -- it's curious how the elderly always
remember their youth but never what they did yesterday! The idea of replicating
neurons is not young, Dr. Joseph Altman reported replicating neurons in
rats decades ago. Dr. Fernando Nottebohm also reported brain rejuvenation
in birds years ago.
Even with new brain cells
being formed, our brain gradually lose cells and weight -- except,
of course, until puberty. What is the relation between the loss of neurons
and the loss of their supporting cells -- called astrocytes or glial cells
-- is unknown to date. When exactly this loss begins is still a mystery,
it might even begin in childhood, we just don't know but it is safe to
assume that it begins at least shortly after our sexual peek -- around
19 years old. There are also areas of the brain that lose more
cells than others. Given the premise that our somatic cells can't replicate
forever -- I'll explain this issue again in my next article --, our brain
cells -- neurons and glial cells -- also don't last forever. Even neurons
that don't replicate probably age and die. Overall, aging does seem to
occur in the brain even if we could change it to a new body at certain
time intervals.
Given the difficulties of
constant transplants to new bodies, we must focus ourselves in trying to
discover a way to stop aging in all the body. Having, of course, the brain
as top priority. In the following articles, I expose another ideas and
directions on how we can achieve this objective.