Biophysical Society Conference | Tahoe 2022

Molecular Biophysics of Membranes

Poster Abstracts

54-POS Board 14 QUANTUM MECHANICS, UNIVERSAL SCALING AND FERROELECTRIC HYSTERESIS REGIMES IN THE GIANT SQUID AXON PROPAGATING ACTION POTENTIAL: A PHASE SPACE APPROACH Nikola Jurisic 1 ; Fred Cooper 2,3 ; 1 Independent researcher, Los Angeles, CA, USA 2 The Santa Fe Institute, Santa Fe, NM, USA 3 Los Alamos National Laboratory, Theoretical Division and Center for Nonlinear Studies, Los Alamos, NM, USA Experiments done 70 years ago on patches of the squid axon membrane describe sodium and potassium currents with parameters of limited physical meaning. The shape of the nerve impulse thus reconstructed is somewhat inaccurate, especially in the recovery region. We have analyzed a simpler experiment, the steady propagation of the fully functioning nerve impulse and have described the ionic currents in terms of known physical phenomena and constants. Displaying currents as functions of potential in the recovery region of the nerve impulse reveals the presence of outgoing overlapping potassium and sodium currents with quasilinear segments. Similarly, the partial overlap of the incoming sodium current and the sodium polarization current is revealed in the rising edge segment. Our fits reveal two different lattices of sodium channels separated by continuous phase changes, one in the rising edge region of the impulse from its inception to its peak and the other in the recovery region. Fits of fractions of open channels using ionic time rates during the nerve impulse reveal the universal role of the dimensionless and temperature independent fine-structure constant from quantum mechanics. We find that the activation energies of ionic currents are of the same order as the rate-limiting metabolic biochemical reactions. Our results will motivate research of the: role of the continuous phase change in the inception of the nerve impulse; role of sodium channel lattices in creation and storage of memories and their pharmacological implications; role of the fine-structure constant in ions traversing ionic channels.

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