Thermal block of action potentials is primarily due to voltage-dependent potassium currents: a modeling study

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 me...

Full description

Published in: Journal of neural engineering Vol. 16; no. 3; p. 036020
Main Authors: Ganguly, Mohit, Jenkins, Michael W, Jansen, E Duco, Chiel, Hillel J
Format: Journal Article
Language: English
Published: England IOP Publishing 04-26-2019
Subjects:
Online Access: Get full text
Summary: 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.
Bibliography: JNE-102519.R2
ISSN: 1741-2560
1741-2552
DOI: 10.1088/1741-2552/ab131b