TY - BOOK

T1 - Studies on the Action Potential From a Thermodynamic Perspective

AU - Wang, Tian

PY - 2017

Y1 - 2017

N2 - Nerve impulse, also called action potential, has mostly been considered as apure electrical phenomenon. However, changes in dimensions, e.g. thicknessand length, and in temperature along with action potentials have been observed,which indicates that the nerve is a thermodynamic system.The work presented in this thesis focuses on the study of the following featuresof nerve impulses, and interpretations from a thermodynamic view are provided.(1) Two impulses propagating toward each other are found to penetrate througheach other upon collision. The penetration is found in both bundles of axonsand nerves with ganglia. (2) Attempts have been made to measure the temperaturechange associated with an action potential as well as an oscillation reaction(Briggs-Rauscher reaction) that shares the adiabatic feature. It turns out thatsome practical issues need to be solved for the temperature measurement of thenerve impulses, while the measured temperature change during the oscillationreaction suggests that there are a reversible adiabatic process and a dissipativeprocess. (3) Local anesthetic e↵ect on nerves is studied. Local anesthetic lidocainecauses a significant stimulus threshold shift of the action potential, and aslight decrease in the conduction velocity. (4) The conduction velocity of nerveimpulses as a function of the diameter of the nerve is investigated with stretchedventral cords from earthworms. The velocity is found to be constant with a decreaseof the diameter, indicating that the conduction velocity is independent ofthe diameter of the nerve. All the above results can be explained by a thermodynamictheory for nerve impulses, i.e. the Soliton theory, which considers thenerve impulses as electromechanical solitons traveling without dissipation.Finally, the magnetic field generated by a nerve impulse is measured with asensitive atomic magnetometer developed by our collaborators from the QuantumOptics (QUANTOP) group in our institute. The magnetometer can be operatedat room or body temperatures, and magnetic field from nerve impulses can bemeasured several millimeters away. This provides a promising technique for medicalapplications.

AB - Nerve impulse, also called action potential, has mostly been considered as apure electrical phenomenon. However, changes in dimensions, e.g. thicknessand length, and in temperature along with action potentials have been observed,which indicates that the nerve is a thermodynamic system.The work presented in this thesis focuses on the study of the following featuresof nerve impulses, and interpretations from a thermodynamic view are provided.(1) Two impulses propagating toward each other are found to penetrate througheach other upon collision. The penetration is found in both bundles of axonsand nerves with ganglia. (2) Attempts have been made to measure the temperaturechange associated with an action potential as well as an oscillation reaction(Briggs-Rauscher reaction) that shares the adiabatic feature. It turns out thatsome practical issues need to be solved for the temperature measurement of thenerve impulses, while the measured temperature change during the oscillationreaction suggests that there are a reversible adiabatic process and a dissipativeprocess. (3) Local anesthetic e↵ect on nerves is studied. Local anesthetic lidocainecauses a significant stimulus threshold shift of the action potential, and aslight decrease in the conduction velocity. (4) The conduction velocity of nerveimpulses as a function of the diameter of the nerve is investigated with stretchedventral cords from earthworms. The velocity is found to be constant with a decreaseof the diameter, indicating that the conduction velocity is independent ofthe diameter of the nerve. All the above results can be explained by a thermodynamictheory for nerve impulses, i.e. the Soliton theory, which considers thenerve impulses as electromechanical solitons traveling without dissipation.Finally, the magnetic field generated by a nerve impulse is measured with asensitive atomic magnetometer developed by our collaborators from the QuantumOptics (QUANTOP) group in our institute. The magnetometer can be operatedat room or body temperatures, and magnetic field from nerve impulses can bemeasured several millimeters away. This provides a promising technique for medicalapplications.

UR - https://soeg.kb.dk/permalink/45KBDK_KGL/fbp0ps/alma99122333793605763

M3 - Ph.D. thesis

BT - Studies on the Action Potential From a Thermodynamic Perspective

PB - The Niels Bohr Institute, Faculty of Science, University of Copenhagen

ER -