Dr. Matan Mussel: Electrical, Chemical and Mechanical Aspects of Acoustic Pulses in Membranes

This talk was given by Dr. Matan Mussel (NIH, USA) at the 2019 conference on "Physics of Excitatory Membranes (POEM)" in Bad Honnef.

Abstract:
"In an ongoing debate on the physical nature of the action potential, one group adheres to the electrical model of Hodgkin and Huxley, while the other describes the action potential as a non-linear acoustic pulse propagating within an interface near a transition. However, despite remarkable similarities, acoustics remains a nonintuitive mechanism for action potentials for the following reason. While acoustic pulses are typically associated with the propagation of density, pressure and temperature variation, action potentials are most commonly measured electrically. Here we demonstrate theoretically that an idealized description of acoustic pulses that traverse a phase transition share many similar properties with action potentials. Furthermore, we show that electrical and pH changes are inseparable from the acoustic pulse, upon considering the electrical and chemical aspects of the interface, in addition to its mechanical properties. Our analysis is based on classical physical principles (e.g., conservation laws and Maxwell electrodynamics) and contains no fit parameters. An implication of this work is that crucial functional information of the cell may be overlooked by focusing only on electrical measurements.

Biology,Physics,Biological Communication,Membrane,Thermodynamics,Action Potentials,Conservation Laws,Pulse Propagation,Excitable Media,Hodgkin-Huxley,Heimburg-Jackson,