I have a question concerning the firing of a neuron. If one were to
place anions around a neuron (in vitro, say, so that the negative
charge wasn't rapidly dissipate), would this make the neuron fire?
If these extra anions (also assume that they are unpermeable) were
put around the axon, they would reduce the potential difference across
it (by making the extracellular fluid less positive). By reducing
the potential difference above the threshold potential difference, the
neuron would fire. Does this reasoning sound correct? It seems to
depend on the proximity of the anions to the neuron's membrane and
the voltage dependence of the Na+ channels (are they dependent on the
potential difference across the membrane, or are there other influences?).
Thanks for the replies in advance,