Mohit Ganguly1,2, Michael W Jenkins3,4, E Duco Jansen1,2, Hillel J Chiel4,5,6. 1. Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States of America. 2. Biophotonics Center, Vanderbilt University, Nashville, TN, United States of America. 3. Department of Pediatrics, Case Western Reserve University, Cleveland, OH, United States of America. 4. Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States of America. 5. Department of Biology, Case Western Reserve University, Cleveland, OH, United States of America. 6. Department of Neurosciences, Case Western Reserve University, Cleveland, OH, United States of America.
Abstract
OBJECTIVE: Thermal block of action potential conduction using infrared lasers is a new modality for manipulating neural activity. It could be used for analysis of the nervous system and for therapeutic applications. We sought to understand the mechanisms of thermal block. APPROACH: To analyze the mechanisms of thermal block, we studied both the original Hodgkin/Huxley model, and a version modified to more accurately match experimental data on thermal responses in the squid giant axon. MAIN RESULTS: Both the original and modified models suggested that thermal block, especially at higher temperatures, is primarily due to a depolarization-activated hyperpolarization as increased temperature leads to faster activation of voltage-gated potassium ion channels. The minimum length needed to block an axon scaled with the square root of the axon's diameter. SIGNIFICANCE: The results suggest that voltage-dependent potassium ion channels play a major role in thermal block, and that relatively short lengths of axon could be thermally manipulated to selectively block fine, unmyelinated axons, such as C fibers, that carry pain and other sensory information.
OBJECTIVE: Thermal block of action potential conduction using infrared lasers is a new modality for manipulating neural activity. It could be used for analysis of the nervous system and for therapeutic applications. We sought to understand the mechanisms of thermal block. APPROACH: To analyze the mechanisms of thermal block, we studied both the original Hodgkin/Huxley model, and a version modified to more accurately match experimental data on thermal responses in the squid giant axon. MAIN RESULTS: Both the original and modified models suggested that thermal block, especially at higher temperatures, is primarily due to a depolarization-activated hyperpolarization as increased temperature leads to faster activation of voltage-gated potassium ion channels. The minimum length needed to block an axon scaled with the square root of the axon's diameter. SIGNIFICANCE: The results suggest that voltage-dependent potassium ion channels play a major role in thermal block, and that relatively short lengths of axon could be thermally manipulated to selectively block fine, unmyelinated axons, such as C fibers, that carry pain and other sensory information.
Authors: Jeremy B Ford; Mohit Ganguly; Megan E Poorman; William A Grissom; Michael W Jenkins; Hillel J Chiel; E Duco Jansen Journal: Lasers Surg Med Date: 2019-07-25 Impact factor: 4.025
Authors: Jialiang Chen; Yihua Zhong; Jicheng Wang; Bing Shen; Jonathan Beckel; William C de Groat; Changfeng Tai Journal: Neuromodulation Date: 2021-12-18
Authors: Junqi Zhuo; Zihui Ou; Yuhan Zhang; Elizabeth M Jackson; Sachin S Shankar; Matthew T McPheeters; Jeremy B Ford; E Duco Jansen; Hillel J Chiel; Michael W Jenkins Journal: Neurophotonics Date: 2021-02-19 Impact factor: 3.593
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