scholarly journals From Action Potential-Clamp to "Onion-Peeling" Technique – Recording of Ionic Currents Under Physiological Conditions

10.5772/35284 ◽  
2012 ◽  
Author(s):  
Ye Chen-Izu ◽  
Leighton T. ◽  
Peter P. ◽  
Tamas Banyasz
Keyword(s):  
Action Potential ◽  
Ionic Currents ◽  
Physiological Conditions ◽  
Action Potential Clamp

scholarly journals Sequential dissection of multiple ionic currents in single cardiac myocytes under action potential-clamp

2011 ◽  
Vol 50 (3) ◽  
pp. 578-581 ◽  
Author(s):  
Tamas Banyasz ◽  
Balazs Horvath ◽  
Zhong Jian ◽  
Leighton T. Izu ◽  
Ye Chen-Izu
Keyword(s):  
Action Potential ◽  
Cardiac Myocytes ◽  
Ionic Currents ◽  
Action Potential Clamp

Linear transformations extract parameters of ionic currents and action potential features from pseudo-ECG in cardiomyocyte models

2020 ◽  
Author(s):  
Salim Baigildin ◽  
Konstantin Ushenin ◽  
Aigul Fabarisova ◽  
Marat Bogdanov ◽  
Olga Solovyeva
Keyword(s):  
Action Potential ◽  
Ionic Currents ◽  
Linear Transformations

scholarly journals Action potential bursts in central snail neurons elicited by paeonol: roles of ionic currents

2010 ◽  
Vol 31 (12) ◽  
pp. 1553-1563 ◽  
Author(s):  
Yi-hung Chen ◽  
Pei-lin Lin ◽  
Hui-yu Hsu ◽  
Ya-ting Wu ◽  
Han-yin Yang ◽  
...  
Keyword(s):  
Action Potential ◽  
Ionic Currents ◽  
Snail Neurons

Basis for tetrodotoxin and lidocaine effects on action potentials in dog ventricular myocytes

1988 ◽  
Vol 254 (6) ◽  
pp. H1157-H1166 ◽  
Author(s):  
J. A. Wasserstrom ◽  
J. J. Salata
Keyword(s):  
Action Potential ◽  
Action Potentials ◽  
Ventricular Myocytes ◽  
Ionic Currents ◽  
Detectable Effect ◽  
Na Channel ◽  
Na Current ◽  
Voltage Range ◽  
Purkinje Fibers ◽  
Ventricular Cells

We studied the effects of tetrodotoxin (TTX) and lidocaine on transmembrane action potentials and ionic currents in dog isolated ventricular myocytes. TTX (0.1-1 x 10(-5) M) and lidocaine (0.5-2 x 10(-5) M) decreased action potential duration, but only TTX decreased the maximum rate of depolarization (Vmax). Both TTX (1-2 x 10(-5) M) and lidocaine (2-5 x 10(-5) M) blocked a slowly inactivating toward current in the plateau voltage range. The voltage- and time-dependent characteristics of this current are virtually identical to those described in Purkinje fibers for the slowly inactivating inward Na+ current. In addition, TTX abolished the outward shift in net current at plateau potentials caused by lidocaine alone. Lidocaine had no detectable effect on the slow inward Ca2+ current and the inward K+ current rectifier, Ia. Our results indicate that 1) there is a slowly inactivating inward Na+ current in ventricular cells similar in time, voltage, and TTX sensitivity to that described in Purkinje fibers; 2) both TTX and lidocaine shorten ventricular action potentials by reducing this slowly inactivating Na+ current; 3) lidocaine has no additional actions on other ionic currents that contribute to its ability to abbreviate ventricular action potentials; and 4) although both agents shorten the action potential by the same mechanism, only TTX reduces Vmax. This last point suggests that TTX produces tonic block of Na+ current, whereas lidocaine may produce state-dependent Na+ channel block, namely, blockade of Na+ current only after Na+ channels have already been opened (inactivated-state block).

Understanding the electrical behavior of the action potential in terms of elementary electrical sources

2015 ◽  
Vol 39 (1) ◽  
pp. 15-26 ◽  
Author(s):  
Javier Rodriguez-Falces
Keyword(s):  
Action Potential ◽  
Action Potentials ◽  
Present Report ◽  
Electrical Potential ◽  
Ionic Currents ◽  
New Approach ◽  
Electrical Potentials ◽  
Proposed Model ◽  
Ionic Mechanisms ◽  
Human Electrophysiology

A concept of major importance in human electrophysiology studies is the process by which activation of an excitable cell results in a rapid rise and fall of the electrical membrane potential, the so-called action potential. Hodgkin and Huxley proposed a model to explain the ionic mechanisms underlying the formation of action potentials. However, this model is unsuitably complex for teaching purposes. In addition, the Hodgkin and Huxley approach describes the shape of the action potential only in terms of ionic currents, i.e., it is unable to explain the electrical significance of the action potential or describe the electrical field arising from this source using basic concepts of electromagnetic theory. The goal of the present report was to propose a new model to describe the electrical behaviour of the action potential in terms of elementary electrical sources (in particular, dipoles). The efficacy of this model was tested through a closed-book written exam. The proposed model increased the ability of students to appreciate the distributed character of the action potential and also to recognize that this source spreads out along the fiber as function of space. In addition, the new approach allowed students to realize that the amplitude and sign of the extracellular electrical potential arising from the action potential are determined by the spatial derivative of this intracellular source. The proposed model, which incorporates intuitive graphical representations, has improved students' understanding of the electrical potentials generated by bioelectrical sources and has heightened their interest in bioelectricity.

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