VERA MAURA FERNANDES DE LIMA

VERA MAURA FERNANDES DE LIMA

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Analyses of HH and GHK equations with another perspective
2021 - TAMAGAWA, HIROHISA; MULEMBO, TITUS; LIMA, VERA M.F. de; HANKE, WOLFGANG
Two mathematically distinct physiological concepts, the Goldman-Hodgkin-Katz eq. (GHK eq.) and the Hodgkin-Huxley model (HH model) were successfully associated with each other in a prior work. The previous work was performed on the following premises (i) The membrane potential is generated by ion adsorption, as opposed to the classical ion transport mechanisms, (ii) The living cell is a thermodynamically real system rather than an ideal system, and (iii) The conductance employed in the HH model is replaced by the ion activity coefficient, which is weighted with the role of conductance. Consequently, the GHK eq. was mathematically associated with the HH model through the intermediary of Boltzmann ion distribution and mass action law. To verify if our theoretical formularization could afford a physiologically, physically and chemically viable model, we performed computational analysis using the formulae (quantitative correlations between various variables) we derived in the previous work. The computational results obtained through associating the GHK eq. with the HH model validated our model and its predictions. This outcome suggests that the current prevailing physiological concepts could be expanded further, to incorporate the newly proposed mechanisms. That is, GHK eq. and HH model could be interpreted via another set of founding principles that incorporate the ubiquitous phenomena of ion-adsorption.
Reversibility of excitation waves in brain and heart and the energy of interfacial water
2021 - LIMA, VERA M.F. de; HANKE, WOLFGANG
In 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.
The spreading depression propagation
2021 - LIMA, VERA M.F. de; PEREIRA JUNIOR, ALFREDO; OLIVEIRA, GUILHERME L. de
At 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.
GHK eq. and HH eq. for a real system is mathematically associable to each other but their physiological interpretation needs a reconsideration
2020 - TAMAGAWA, HIROHISA; MULEMBO, TITUS; LIMA, VERA M.F. de; HANKE, WOLFGANG
Despite the long and broad acceptance of the Goldman - Hodgkin - Katz equation (GHK eq.) and the Hodgkin - Huxley equation (HH eq.) as strong tools for the quantitative analysis of the membrane potential behavior, for a long time they have been utilized as separate concepts. That is the GHK eq. and the HH eq. have not been associated with each other mathematically. In this paper, an attempt to associate these equations to each other mathematically was demonstrated and was successful by viewing the system in question as a thermodynamically real system rather than an ideal system. For achieving that, two fundamental physical chemistry concepts, the mass action law, and the Boltzmann distribution were employed. Hence, this paper’s achievement is completely within the framework of common thermodynamics. Through this work, the origin of the membrane potential generation attributed to the ion adsorption-desorption process and governed by the mass action law and the Boltzmann distribution is expressed to be plausible, whereas the existing membrane potential generation mechanism states that membrane potential is generated by transmembrane ion transport. As at this moment, this work does not intend to deny the transmembrane ion transport as a membrane potential generation mechanism but urges the readers to reconsider its validity, since this work suggests that the ion adsorptiondesorption mechanism is as plausible as the transmembrane ion transport mechanism as a cause of membrane potential generation.
Extracellular matrix and its role in conveying glial/neural interactions in health and disease
2017 - LIMA, VERA M.F. de; HANKE, WOLFGANG
We review the concepts and findings that may be related to the occurrence of non-linear glial/neural dynamics involving interactions between polyelectrolytes of the extracellular matrix and the basement membranes that cover the endfeet of glia at CNS interfaces. Distortions of perception and blocking of learning expressed in functional syndromes are interpreted as macroscopic electrochemical patterns that emerge in grey matter through glial/neural interactions.
Macroscopic self-organized electrochemical patterns in excitable tissue and irreversible thermodynamics
2016 - LIMA, VERA M.F. de; HANKE, WOLFGANG
In this paper we make the assertion that the key to understand the emergent properties of excitable tissue (brain and heart) lies in the application of irreversible thermodynamics. We support this assertion by pointing out where symmetry break, phase transitions both in structure of membranes as well as in the dynamic of interactions between membranes occur in excitable tissue and how they create emergent low dimensional electrochemical patterns. These patterns are expressed as physiological or physiopathological concomitants of the organ or organism behavior. We propose that a set of beliefs about the nature of biological membranes and their interactions are hampering progress in the physiology of excitable tissue. We will argue that while there is no direct evidence to justify the belief that quantum mechanics has anything to do with macroscopic patterns expressed in excitable tissue, there is plenty of evidence in favor of irreversible thermodynamics. Some key predictions have been fulfilled long time ago and they have been ignored by the mainstream literature. Dissipative structures and phase transitions appear to be a better conceptual context to discuss biological self-organization. The central role of time as a global coupling agent is emphasized in the interpretation of the presented results.
Microgravity dependence of excitable biological and physicochemical media
2006 - HANKE, W.; LIMA, V.M.F. de; WIEDEMANN, M.; MEISSNER, K.
The plastic glial-synaptic dynamics within the neuropil: A self-organizing system composed of polyelectrolytes in phase transition
2016 - LIMA, VERA M.F. de; PEREIRA JUNIOR, ALFREDO
The lesson from snake venom: ion transport and glycolysis are couple through the pumping rate of the Na/KAT pase
2007 - LIMA, V.M.F. de; HANKE, W.; CAMILLO, M.A.; SPENCER, P.; NASCIMENTO, N.
Biphasic optical signal of an oscillating nonstationary belousov-zhabotinsky bulk reactions and its similarity to some neurophysiological events
2007 - DOLZMANN, K.; KALTENBACH, S.; HANKE, W.; FERNANDES de LIMA, V.M.