Re:Terminal spreading depolarization and electrical silence ...
by Terr_ on Monday March 12, 2018 @03:19PM
(#16570612)
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.
> 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.