Single potassium channel conductance in the frog node of Ranvier

The single K+-channel conductance was calculated from the variance of the spontaneous potassium noise currents in voltage clamped frog node. Essential for this calculation is the mean potassium conductance during the noise measurement. So far this quantity has been underestimated, apparently due to K+-ion accumulation. With the proper values, the single K+-channel conductance is an increasing function of membrane voltage.