Reliability of ionic current measurements in Ranvier nodes.

A mathematical formalism was developed comprising four performance parameters to analyse electronic feedback systems for voltage clamp measurements in myelinated nerve fibres. The effects of the so-called Schmidt-Lanterman incisures and of the nodal series resistance were of particular interest here. Starting from passive standard data from myelinated nerve fibres, we calculated the frequency dependence of the above mentioned parameters for the measuring systems according to Nonner, to Dodge and Frankenhaeuser, and to Bohuslavizki and coworkers. It turned out that the latter system is clearly preferable to the two remaining systems for ionic current measurements in Ranvier nodes.