title: Conduction block in myelinated axons induced by high-frequency (kHz) non-symmetric biphasic stimulation.
abstract: This study used the Frankenhaeuser-Huxley axonal model to analyze the effects of non-symmetric waveforms on conduction block of myelinated axons induced by high-frequency (10-300 kHz) biphasic electrical stimulation. The results predict a monotonic relationship between block threshold and stimulation frequency for symmetric waveform and a non-monotonic relationship for non-symmetric waveforms. The symmetric waveform causes conduction block by constantly activating both sodium and potassium channels at frequencies of 20-300 kHz, while the non-symmetric waveforms share the same blocking mechanism from 20 kHz up to the peak threshold frequency. At the frequencies above the peak threshold frequency the non-symmetric waveforms block axonal conduction by either hyperpolarizing the membrane (if the positive pulse is longer) or depolarizing the membrane (if the negative pulse is longer). This simulation study further increases our understanding of conduction block in myelinated axons induced by high-frequency biphasic electrical stimulation, and can guide future animal experiments as well as optimize stimulation parameters that might be used for electrically induced nerve block in clinical applications.
authors.affiliation: Department of Urology, University of Pittsburgh Pittsburgh, PA, USA ; Department of Biomedical Engineering, Beijing Jiaotong University Beijing, China.
authors.forename: Shouguo
authors.initials: S
authors.lastname: Zhao
authors.affiliation: Department of Urology, University of Pittsburgh Pittsburgh, PA, USA ; Department of Biomedical Engineering, Beijing Jiaotong University Beijing, China.
authors.forename: Guangning
authors.initials: G
authors.lastname: Yang
authors.affiliation: Department of Urology, University of Pittsburgh Pittsburgh, PA, USA.
authors.forename: Jicheng
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Pharmacology and Chemical Biology, University of Pittsburgh Pittsburgh, PA, USA.
authors.forename: James R
authors.initials: JR
authors.lastname: Roppolo
authors.affiliation: Department of Pharmacology and Chemical Biology, University of Pittsburgh Pittsburgh, PA, USA.
authors.forename: William C
authors.initials: WC
authors.lastname: de Groat
authors.affiliation: Department of Urology, University of Pittsburgh Pittsburgh, PA, USA ; Department of Pharmacology and Chemical Biology, University of Pittsburgh Pittsburgh, PA, USA.
authors.forename: Changfeng
authors.initials: C
authors.lastname: Tai
keywords: block; high-frequency; model; nerve; simulation