www.neuron.yale.edu

Hello!


As you know, in the membrane of cell we have some voltage activated-gate channel and some pumps like Na/K or Ca/K,..

My questions are:

Dose "leak current" paly role of Na/K pump?

Doese the effect of pumps on ionic concentration in extracellular and intracellular space is negligible respect to ionic current inward or outward the cell?

In most Hodgkin-Huxley style models the ion-pumps are not modeled, instead it is assumed that the passive currents do not significantly change ion-distribution between the cells in- and outside. This then results in constant reversal potentials. For some ion-channels, like calcium dependent cation-channels the calcium ion-concentration needs to be modeled explicitly and then also pump/decay-mechanisms have to be implemented. The other ionic pump currents are in general not modeled explicitly and therefore restoring the resting membrane potential takes place via the passive conductance which therefore contains the ion-pump currents.