Biophysics of Action Potential

An integrated view of the action potential that takes into account electrical, mechanical, thermal and chemical aspects is currently lacking. Most of the experimental and theoretical efforts were targeted towards understanding the electrical component of the action potential.

Towards this effort of developing a more complete biophysical framework for neuronal information processing , I proposed along with Ben Machta (Lewis Sigler Institute for integrative genomics, Princeton University) a theoretical model that accounts for mechanical displacements associated with action potential. We termed the mechanical surface waves associated with the action potential:  "Action waves” (AW).  Our model for these AWs allows us to predict, in terms of elastic constants, axon radius and axoplasmic density and viscosity, the shape of the AW that should accompany any traveling wave of voltage. We show that our model makes predictions that are in agreement with results in experimental systems including the garfish olfactory nerve and the squid giant axon. We expect our model to serve as a framework for understanding the physical origins and possible functional roles of these AWs in neurobiology (1)

Questions arising from our AW theory are: Are the mechanical changes associated with the action potential propagation (aka Action Waves) an epiphenomenon or has functional implications ? Do the action waves contribute to the action potential initiation ? What advantages do surface waves confer to neural information processing ?  Does the precise structure of the cytoskeleton play a role in shaping the mechanical aspects of the Action Potential?