Compensation of the low-pass filter properties of the current measuring internode in potential-clamped myelinated nerve fibres

The bandwidth of membrane current measurements in potential-clamped Ranvier nodes is limited by the low-pass filter properties of the internodes. If about 35% of the current measuring internode is grounded via an additional electrode, the bandwidth of this internode increases by a factor of about 40. Consequently, in potential clamp experiments the measured time course of the early ionic currents changes markedly, while the duration of the capacity current is shortened.