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Rocking horse people eat marshmallow pies © Robert Sommers 2017

Friday, May 10, 2013

Deathwave

The other side © Robert Sommers 2013

The waves of death engulfed me; the currents of chaos overwhelmed me. 2 Samuel 22:5

Those that are close to me know that I have been in a very dark mood the last few weeks, if not months. What better time to discuss the wave of death? Scientists have tried in vain to understand what happens in the moments during brain death, particularly that odd 5 to 15 second period where the brain sends out a high frequency signal, perhaps signaling the mother ship for docking instructions.

From Discover.com Brain waves surge moments before death:
A study of seven terminally ill patients found identical surges in brain activity moments before death, providing what may be physiological evidence of "out of body" experiences reported by people who survive near-death ordeals.
Doctors at George Washington University Medical Faculty Associates recorded brain activity of people dying from critical illnesses, such as cancer or heart attacks.
Moments before death, the patients experienced a burst in brain wave activity, with the spikes occurring at the same time before death and at comparable intensity and duration.
Writing in the October issue of the Journal of Palliative Medicine, the doctors theorize that the brain surges may be tied to widely reported near-death experiences which typically involve spiritual or religious attributes.
These researchers decapitated rats and found that a minute later they broadcast this high amplitude signal, a process they say might be reversible.

This scientific paper, Neural Dynamics during Anoxia and the “Wave of Death” offered some explanations for the occurrence.

Abstract

Recent experiments in rats have shown the occurrence of a high amplitude slow brain wave in the EEG approximately 1 minute after decapitation, with a duration of 5–15 s (van Rijn et al, PLoS One 6, e16514, 2011) that was presumed to signify the death of brain neurons. We present a computational model of a single neuron and its intra- and extracellular ion concentrations, which shows the physiological mechanism for this observation. The wave is caused by membrane potential oscillations, that occur after the cessation of activity of the sodium-potassium pumps has lead to an excess of extracellular potassium. These oscillations can be described by the Hodgkin-Huxley equations for the sodium and potassium channels, and result in a sudden change in mean membrane voltage. In combination with a high-pass filter, this sudden depolarization leads to a wave in the EEG. We discuss that this process is not necessarily irreversible.

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