
Terminal spreading depolarization and electrical silence in death of human brain - mrleiter
http://onlinelibrary.wiley.com/doi/10.1002/ana.25147/full
======
jlebar
_we performed recordings with either subdural electrode strips (n = 4) or
intraparenchymal electrode arrays (n = 5) in patients with devastating brain
injury that resulted in activation of a Do Not Resuscitate–Comfort Care order
followed by terminal extubation._

Wow. That must have been some IRB meeting.

------
Terr_
I don't know enough to determine which part is the most important, but this
sounds interesting:

> In animals, complete global ischemia causes complete electrical inactivity
> (ie, isoelectricity) of affected gray matter within about 20 to 40 seconds.
> This cerebral silencing is regarded as an austerity program to curb neuronal
> energy usage by the shutdown of nonessential cell functions well before the
> neuronal adenosine triphosphate (ATP) pool is depleted and prospects of
> tissue recovery vanish. [...]

> Despite this austerity program, sodium and calcium always leak into cells
> and potassium leaks out. [...] When a threshold level of failure, usually
> reached 1 to 5 minutes after nonspreading depression, has rendered the
> ischemic tissue isoelectric, neurons then undergo abrupt, nonlinear rundown
> in the ion gradients across the cellular membranes. This depolarization
> develops en masse from either one or multiple foci and spreads in the tissue
> as a self-propagating wave.

Attempted TLDR: Not enough fresh blood and neurons go into a crisis mode to
stay alive. However, they keep leaking electrically-important stuff, and once
past a point there's a fast-spreading wave of doom through the neuron that
really kills it.

------
trhway
>neurons then undergo abrupt, nonlinear rundown in the ion gradients across
the cellular membranes.

that should generate a [miniscule] EM wave.

>This depolarization develops en masse from either one or multiple foci and
spreads in the tissue as a self-propagating wave.

so a very sensitive EM detector should see a burst of EM radiation. One can
wonder whether some [very sensitive to EM] people may perceive that as
"departing soul" (and technically that burst of radiation does have the
imprint of the neuronal configuration which generated it). Also one can wonder
(well it can be calculated/measured i suppose) whether that burst of EM
radiation can cause some electrostatic effects and or some kind of
luminescence around the body in say very dry air or the air with very fine
dust or in presence of some non-typical gases or liquid drops suspended in the
air.

~~~
jackhack
>>One can wonder whether some [very sensitive to EM] people

What sort of people are those? Are we talking about "psychics?"

~~~
trhway
"psychics" type of activities are mostly about "souls"/etc long after the
original death event. I don't yet know a good rationalization for that.

People have various ranges of abilities/sensitivities and i just theoretically
allow for outliers like one or two orders of magnitude difference for some
people (or a mutation producing for example something along the lines of that
magnetic field vision that birds have (some molecule in their eyes acting like
a compass))

------
CptFribble
Of course this has me thinking of possible interventions - maybe a substance
that interacts with neuron cell walls to stop Na/Ca/K leakage? Of course, it
would have to be fast-acting, non-toxic on the way in, reversible, and non-
toxic on the way out.

Could any experts comment and inform if such a thing is inside the realm of
possibility as we know it?

------
iandanforth
Does the shut down of spontaneous activity due to lack of oxygen/blood account
for why people pass out in choke-holds? Or is this a different process?

------
thunderman10
I can't be the only one who thought this article was about the dangers of
using a Linux terminal instead of GUI.

~~~
dllthomas
There was a momentary "wow, which terminal?" before realizing the headline
surely intended an alternative reading.

