VERA MAURA FERNANDES DE LIMA
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Artigo IPEN-doc 27836 Reversibility of excitation waves in brain and heart and the energy of interfacial water2021 - LIMA, VERA M.F. de; HANKE, WOLFGANGIn this manuscript, we interpret the implications of a discovery we made in 1993 for the understanding of the spread of excitation waves in axon, central gray matter (isolated retina) and heart. We propose that the initial burst of energy dissipation in these waves measured as potentials drops, ionic activities marked changes or optical properties being mostly the effect of dissociated water becoming liquid water and be reversible due to the further on dissociation during the refractory period. We also propose experiments in order to falsify or agree with this conjecture.Artigo IPEN-doc 27713 The spreading depression propagation2021 - LIMA, VERA M.F. de; PEREIRA JUNIOR, ALFREDO; OLIVEIRA, GUILHERME L. deAt the transition from quiescence to propagating waves recorded in isolated retinas, a circular electric current closes in the extracellular matrix; this circular current creates a magnetic torus flow that, when entering quiescent tissue in front of the wave, recruits elements and when leaving behind, helps to build the absolute refractory state. The waving magnetic torus is the consequence of the vortex effect and explains the energy boost that drives propagation. Methods: We interpret experimental results from intrinsic and extrinsic fluorescence dyes, voltage, calcium and pH sensitive, optical signals from isolated retinas, and time series recordings using ion exchange resins: Ca, K, pH, Na, Cl recorded extracellularly at retinas, cerebellums and cortices coupled to spreading depression waves. Finally, we checked the ECoG activity, also a time series, at the transition from after discharges to spreading depression in rat hippocampus. Results: The integrated assessment of the diversified measurements led to the realization that the magnetic flow at the wavefront is a major contributor to the wave propagation mechanisms. This flow couples mass and charge flows as a swirling torus from excited to quiescent tissue. Conclusions: An alternative model of the brain is possible, apart from the classical HH and molecular biology model. Physical chemistry of charged gels and its flows explains the results. The conceptual framework uses far from equilibrium thermodynamics.