Get Published | Subscribe | About | Write for Our Blog    

Posted on April 18, 2019 at 11:56 PM
By Jon Holmlund

The latest mind-blowing (seriously, no pun intended) report
from the science literature is that a team of scientists at Yale Medical School
have been able to use an artificial preservative solution to recover electrical
activity in some of the cells of the brains from the severed heads of pigs that
had been slaughtered for food.  This is
absolutely stunning because the understanding—so widely accepted that the term
“conventional wisdom” is trite in this case—that the brain’s need for
oxygen, nutrients, and the blood flow that provides them is so massive, so
constant that an interruption of even a few minutes means irreversible death of
brain tissue.  This can be in part of the
brain (as in a stroke), or the whole brain (as in brain death).  Your correspondent is not a neuroscientist,
but understands that recent research is showing the human brain, anyway, to be
more adaptable than historically understood, meaning that after an event like a
stroke, function can be restored over time with rehabilitative efforts that
support the remaining, undamaged brain tissue adapting to the damage.

In this case, it was four
hours
after the pigs’ deaths that the researchers isolated their brains and
put them into the solutions.  Besides the
electrical activity in some nerve cells, the researchers also found evidence
that blood vessels could support circulation, and that there was metabolic
(energy-using) activity in the isolated brains. 
Evidence that the whole brain was working, and able to, for example,
“feel” pain or detect stimuli, was not evident, but the researchers
were not trying to do that.  Their
immediate goal was apparently to understand how long brain cell function might
be preserved.

Before we rush to invoke the immortal Viktor Frankenstein,
it should be said that the researchers in this case appear to have carefully
followed existing ethical guidelines for the research use of animals.  And it is tempting to speculate about this
work leading to new treatments for brain injury.

Still, many ethical issues are raised.  What constraints should proper ethics of
experimentation on animals put on future, similar experiments?  Is it acceptable to pursue a model for whole
animal or even human brains preserved outside the body to study preservation
and restoration of function, perhaps even to the point of trying to “jump
start” the whole brain, as the current researchers speculate might be
necessary.  Or, such a recovery might be
impossible; they say they might just be observing an evitable process of brain
death and decay.  Maybe it takes rather
longer than previously appreciated.

That last point raises further concerns about how we
understand when death has occurred.  Do
current approaches toward harvesting human organs for transplantation, that may
require that blood flow to the brain be interrupted for only a matter of
minutes before declaring death of the donor, effectively jump the gun?  Might some people who are thought brain dead
in fact have better chance of recovery than appreciated?  These questions already trouble ethicists
thinking about how to determine when a person has died.

These are only a few of the concerns, and some authors this
week are calling for an international review of the ethics of this work, before
proceeding further with research on mammals—never mind humans, that’s not in
view, yet.

A
summary of the work for the non-specialist is openly available
.  Summaries of related ethical issues, also
openly available, can be found here
and here.  The full
scientific report in Nature

requires subscription or purchase.

Comments are closed.