title: Reactive species modify NaV1.8 channels and affect action potentials in murine dorsal root ganglion neurons.
abstract: Dorsal root ganglion (DRG) neurons are important relay stations between the periphery and the central nervous system and are essential for somatosensory signaling. Reactive species are produced in a variety of physiological and pathophysiological conditions and are known to alter electric signaling. Here we studied the influence of reactive species on the electrical properties of DRG neurons from mice with the whole-cell patch-clamp method. Even mild stress induced by either low concentrations of chloramine-T (10 μM) or low-intensity blue light irradiation profoundly diminished action potential frequency but prolonged single action potentials in wild-type neurons. The impact on evoked action potentials was much smaller in neurons deficient of the tetrodotoxin (TTX)-resistant voltage-gated sodium channel NaV1.8 (NaV1.8(-/-)), the channel most important for the action potential upstroke in DRG neurons. Low concentrations of chloramine-T caused a significant reduction of NaV1.8 peak current and, at higher concentrations, progressively slowed down inactivation. Blue light had a smaller effect on amplitude but slowed down NaV1.8 channel inactivation. The observed effects were less apparent for TTX-sensitive NaV channels. NaV1.8 is an important reactive-species-sensitive component in the electrical signaling of DRG neurons, potentially giving rise to loss-of-function and gain-of-function phenomena depending on the type of reactive species and their effective concentration and time of exposure.
authors.affiliation: Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena & Jena University Hospital, Hans-Knöll-Str. 2, 07745, Jena, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Schink
authors.affiliation: Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena & Jena University Hospital, Hans-Knöll-Str. 2, 07745, Jena, Germany.
authors.forename: Enrico
authors.initials: E
authors.lastname: Leipold
authors.affiliation: Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena & Jena University Hospital, Hans-Knöll-Str. 2, 07745, Jena, Germany.
authors.forename: Jana
authors.initials: J
authors.lastname: Schirmeyer
authors.affiliation: Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena & Jena University Hospital, Hans-Knöll-Str. 2, 07745, Jena, Germany.
authors.forename: Roland
authors.initials: R
authors.lastname: Schönherr
authors.affiliation: Department of Physiology, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Toshinori
authors.initials: T
authors.lastname: Hoshi
authors.affiliation: Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena & Jena University Hospital, Hans-Knöll-Str. 2, 07745, Jena, Germany. Stefan.H.Heinemann@uni-jena.de.
authors.forename: Stefan H
authors.initials: SH
authors.lastname: Heinemann
mesh_terms: D000200:Action Potentials; D000818:Animals; D002478:Cells, Cultured; D005727:Ganglia, Spinal / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D062559:NAV1.8 Voltage-Gated Sodium Channel / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism* / Q000502:physiology; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: D062559:NAV1.8 Voltage-Gated Sodium Channel; D017382:Reactive Oxygen Species; C568318:Scn10a protein, mouse
keywords: Aging; Pain; Radical stress; Reactive oxygen species; Scn10a; Sodium channel