The electrical behavior of the Xenopus laevis nerve fibers was studied when combined electrical (cuff electrodes) and optical (infrared laser, low power sub-5mW) stimulations are applied. Assuming that the main effect of the laser irradiation on the nerve tissue is the localized temperature increase, this paper analyzes and gives new insights into the function of the combined thermoelectric stimulation on both excitation and blocking of the nerve action potentials (AP). The calculations involve a finite-element model (COMSOL) to represent the electrical properties of the nerve and cuff. Electric-field distribution along the nerve was computed for the given stimulation current profile and imported into a NEURON model, which was built to simulate the electrical behavior of myelinated nerve fiber under extracellular stimulation. The main result of this study of combined thermoelectric stimulation showed that local temperature increase, for the given electric field, can create a transient block of both the generation and propagation of the APs. Some preliminary experimental data in support of this conclusion are also shown.
Bibliographical noteFunding Information:
Manuscript received October 24, 2011; revised February 27, 2012; accepted March 20, 2012. Date of publication April 9, 2012; date of current version May 18, 2012. This work was supported in part by the U.K. Engineering and Physical Sciences Research Council under Grant EP/H024581. The work of Z. Mou was supported by the China Scholarship Council. The work of K. Nikolic was supported in part by the EU SeeBetter Project 270324. Asterisk indicates corresponding author.
- Extracellular stimulation
- finite-element method
- heat block
- neural engineering