Mechanics and electromagnetism, together at last in neurobiochemistry
Potassium, sodium, chlorine, and calcium ions in nerve cells have osmotic and electrostatic forces acting on them. Normally they can’t cross the cell membrane, but when ion channels open they rush into/out of the cell trying to reach osmotic equilibrium, and carrying their charge with them. This changes the cell’s voltage with respect to the environment; this is how the neuron fires.
The tendency of these ions to flow is actually a chemical effect, not an electrical one: osmosis is the primary driver. But the tendency to flow in this way can be quantified and calculated exactly like a voltage difference across very high resistance. Even though the ions want to flow to equalize this so-called voltage differential, ordinarily they can’t.
It’s potential potential, in the fullest physics sense of both words.
BWAHAHAHAHAHAHAHAHAHAHAHAHA! I love cognitive science.
upd 8 nov: revised first para, sorry for bumping everyone’s rss feeds