Determination and compensation of series resistances during whole-cell patch-clamp recordings using an active bridge circuit and the phase-sensitive technique

Riedemann, Therese; Polder, Hans Reiner und Sutor, Bernd (2016): Determination and compensation of series resistances during whole-cell patch-clamp recordings using an active bridge circuit and the phase-sensitive technique. In: Pflugers Archiv-European Journal of Physiology, Bd. 468, Nr. 10: S. 1725-1740

Abstract

We present a technique which combines two methods in order to measure the series resistance (R (S)) during whole-cell patch-clamp recordings from excitable and non-excitable cells. R (S) is determined in the amplifier's current-clamp mode by means of an active bridge circuit. The correct neutralization of the electrode capacitance and the adjustment of the bridge circuit is achieved by the so-called phase-sensitive method: Short sine wave currents with frequencies between 3 and 7 kHz are injected into the cells. Complete capacitance neutralization is indicated by the disappearance of the phase lag between current and voltage, and correct bridge balance is indicated by a minimized voltage response to the sine wave current. The R (S) value determined in the current-clamp mode then provides the basis for R (S) compensation in the voltage-clamp recording mode. The accuracy of the procedure has been confirmed on single-compartment cell models where the error amounted to 2-3 %. Similar errors were observed during dual patch clamp recordings from single neocortical layer 5 pyramidal cells where one electrode was connected to the bridge amplifier and the other one to a time-sharing, single-electrode current- and voltage-clamp amplifier with negligible R (S). The technique presented here allows R (S) compensation for up to 80-90 %, even in cells with low input resistances (e.g., astrocytes). In addition, the present study underlines the importance of correct R (S) compensation by showing that significant series resistances directly affect the determination of membrane conductances as well as the kinetic properties of spontaneous synaptic currents with small amplitudes.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Medizin
• Themengebiete: 600 Technik, Medizin, angewandte Wissenschaften > 610 Medizin und Gesundheit
• ISSN: 0031-6768
• Sprache: Englisch