Terminal spreading depolarization and electrical silence in death of human brain | Hacker News Reader

Terminal spreading depolarization and electrical silence in death of human brain

onlinelibrary.wiley.com

66 pointsmrleiter12 comments

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.

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.

>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.

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

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

OP probably chose the vague and general "[very sensitive to EM] people" exactly to avoid labeling.

"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))

Given how quickly EM radiation attenuates with distance, I find the idea of a human detector ludicrous. I’ve also never heard of “EM sensitive” people who have been proven to be something other than nuts. In this particular case the activity would be so faint you’d probably need a MEG or drill through the skull and implant electrodes to detect it.

Saying that a human could do the same from a distance is magic masquerading as pseudoscience.

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?

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?

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

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

Yes, I too reached for my adm5 manual

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