Jialiang Chen1, Yihua Zhong2, Jicheng Wang3, Bing Shen3, Jonathan Beckel4, William C de Groat4, Changfeng Tai5. 1. Department of Urology, University of Pittsburgh, Pittsburgh, PA, USA; Department of Urology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China. 2. Department of Urology, University of Pittsburgh, Pittsburgh, PA, USA; School of Biomedical Engineering, Capital Medical University, Beijing, China. 3. Department of Urology, University of Pittsburgh, Pittsburgh, PA, USA. 4. Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA. 5. Department of Urology, University of Pittsburgh, Pittsburgh, PA, USA; Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA. Electronic address: cftai@pitt.edu.
Abstract
OBJECTIVES: This study aims to determine temperature effect on nerve conduction block induced by high-frequency (kHz) biphasic stimulation (HFBS). MATERIALS AND METHODS: Frog sciatic nerve-muscle preparation was immersed in Ringer's solution at a temperature of 15 or 20 °C. To induce muscle contractions, a bipolar cuff electrode delivered low-frequency (0.25 Hz) stimulation to the nerve. To induce nerve block, a tripolar cuff electrode was placed distal to the bipolar cuff electrode to deliver HFBS (2 or 10 kHz). A bipolar hook electrode distal to the blocking electrode was used to confirm that the nerve block occurred locally at the site of HFBS. A thread tied onto the foot was attached to a force transducer to measure the muscle contraction force. RESULTS: At 15 °C, both 2- and 10-kHz HFBSs elicited an initial transient muscle contraction and then produced nerve block during the stimulation (ie, acute block), with the 10 kHz having a significantly (p < 0.001) higher acute block threshold (5.9 ± 0.8 mA peak amplitude) than the 2 kHz (1.9 ± 0.3 mA). When the temperature was increased to 20 °C, the acute block threshold for the 10-kHz HFBS was significantly (p < 0.0001) decreased from 5.2 ± 0.3 to 4.4 ± 0.2 mA, whereas the 2-kHz HFBS induced a tonic muscle contraction during the stimulation but elicited nerve block after terminating the 2-kHz HFBS (ie, poststimulation block) with an increased block duration at a higher stimulation intensity. CONCLUSION: Temperature has an important influence on HFBS-induced nerve block. The blocking mechanisms underlying acute and poststimulation nerve blocks are likely to be very different.
OBJECTIVES: This study aims to determine temperature effect on nerve conduction block induced by high-frequency (kHz) biphasic stimulation (HFBS). MATERIALS AND METHODS: Frog sciatic nerve-muscle preparation was immersed in Ringer's solution at a temperature of 15 or 20 °C. To induce muscle contractions, a bipolar cuff electrode delivered low-frequency (0.25 Hz) stimulation to the nerve. To induce nerve block, a tripolar cuff electrode was placed distal to the bipolar cuff electrode to deliver HFBS (2 or 10 kHz). A bipolar hook electrode distal to the blocking electrode was used to confirm that the nerve block occurred locally at the site of HFBS. A thread tied onto the foot was attached to a force transducer to measure the muscle contraction force. RESULTS: At 15 °C, both 2- and 10-kHz HFBSs elicited an initial transient muscle contraction and then produced nerve block during the stimulation (ie, acute block), with the 10 kHz having a significantly (p < 0.001) higher acute block threshold (5.9 ± 0.8 mA peak amplitude) than the 2 kHz (1.9 ± 0.3 mA). When the temperature was increased to 20 °C, the acute block threshold for the 10-kHz HFBS was significantly (p < 0.0001) decreased from 5.2 ± 0.3 to 4.4 ± 0.2 mA, whereas the 2-kHz HFBS induced a tonic muscle contraction during the stimulation but elicited nerve block after terminating the 2-kHz HFBS (ie, poststimulation block) with an increased block duration at a higher stimulation intensity. CONCLUSION: Temperature has an important influence on HFBS-induced nerve block. The blocking mechanisms underlying acute and poststimulation nerve blocks are likely to be very different.
Authors: Wenbin Guo; Katherine Shapiro; Zhaoxia Wang; Kody Armann; Bing Shen; Jicheng Wang; James R Roppolo; William C de Groat; Changfeng Tai Journal: Exp Neurol Date: 2021-02-24 Impact factor: 5.330
Authors: Mohit Ganguly; Jeremy B Ford; Junqi Zhuo; Matthew T McPheeters; Michael W Jenkins; Hillel J Chiel; E Duco Jansen Journal: Neurophotonics Date: 2019-10-15 Impact factor: 3.593