title: Enhanced Monitoring of Nanosecond Electric Pulse-Evoked Membrane Conductance Changes in Whole-Cell Patch Clamp Experiments.
abstract: Patch clamp electrophysiology serves as a powerful method for studying changes in plasma membrane ion conductance induced by externally applied high-intensity nanosecond electric pulses (NEPs). This paper describes an enhanced monitoring technique that minimizes the length of time between pulse exposure and data recording in a patch-clamped excitable cell. Whole-cell membrane currents were continuously recorded up to 11 ms before and resumed 8 ms after delivery of a 5-ns, 6 MV/m pulse by a pair of tungsten rod electrodes to a patched adrenal chromaffin cell maintained at a holding potential of -70 mV. This timing was achieved by two sets of relay switches. One set was used to disconnect the patch pipette electrode from the pre-amplifier and connect it to a battery to maintain membrane potential at -70 mV, and also to disconnect the reference electrode from the amplifier. The other set was used to disconnect the electrodes from the pulse generator until the time of NEP/sham exposure. The sequence and timing of both sets of relays were computer-controlled. Using this procedure, we observed that a 5-ns pulse induced an instantaneous inward current that decayed exponentially over the course of several minutes, that a second pulse induced a similar response, and that the current was carried, at least in part, by Na+. This approach for characterizing ion conductance changes in an excitable cell in response to NEPs will yield information essential for assessing the potential use of NEP stimulation for therapeutic applications.
authors.affiliation: Department of Electrical and Biomedical Engineering, College of Engineering, University of Nevada, Reno, Reno, NV, 89557, USA.
authors.forename: Jihwan
authors.initials: J
authors.lastname: Yoon
authors.affiliation: Department of Pharmacology, University of Nevada School of Medicine, Reno, NV, 89557, USA.
authors.forename: Normand
authors.initials: N
authors.lastname: Leblanc
authors.affiliation: Department of Electrical and Biomedical Engineering, College of Engineering, University of Nevada, Reno, Reno, NV, 89557, USA.
authors.forename: Josette
authors.initials: J
authors.lastname: Zaklit
authors.affiliation: Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, 23508, USA.
authors.forename: P Thomas
authors.initials: PT
authors.lastname: Vernier
authors.affiliation: Department of Electrical and Biomedical Engineering, College of Engineering, University of Nevada, Reno, Reno, NV, 89557, USA.
authors.forename: Indira
authors.initials: I
authors.lastname: Chatterjee
authors.affiliation: Department of Pharmacology, University of Nevada School of Medicine, Reno, NV, 89557, USA. gcraviso@medicine.nevada.edu.
authors.forename: Gale L
authors.initials: GL
authors.lastname: Craviso
mesh_terms: D000818:Animals; D002417:Cattle; D019439:Chromaffin Cells / Q000502:physiology; D055724:Electrophysiological Phenomena; D004594:Electrophysiology / Q000295:instrumentation / Q000379:methods; D008564:Membrane Potentials; D018408:Patch-Clamp Techniques / Q000295:instrumentation / Q000379:methods
keywords: Membrane conductance; Nanosecond electric pulse (NEP); Patch clamp whole-cell recording