In article <4448tc$joq at merkurius.lu.se>, biv94cjn at lustudat.student.lu.se
(Armilius) writes:
> If you put potassium in the extracellular fluid outside a frog nerv.
> What is happening to actionpotential then?. What is happening to
> the cellmecanism? What is happening to the membranpotential.
>> Sincerly regards Carl-_Magnus
>
Hi there,
I personally never checked it out, but according to common sense and the
Nernst- equatation, it will lower the membranpotential, because the gradient
for potassium inside vs. outside is lowered. Depending on the potassium amount
in the bath the resting potential is approaching the activation- threshold,
resulting in a higher excitability, after that, continiously increasing the
extracellular potassium amount, the membranpotential will break down,
resulting in a quiet nerve.
These problems are well known in medicine, as a consequence of tourniquet-
syndrom or renal- failures, both resulting in a hyperkaliema with the problem
of cardiac dysrhythmia/arhythmia (and other neurological symptoms).
You can read this (better and in more detail) in all regular neuroscience
textbooks.
Michael.
