A theoretical model of action potential propagation in a thick strand of cardiac muscle is presented. The calculation takes into account the anisotropic and syncytial properties of the tissue, the presence of the interstitial space, the effect of the surrounding tissue bath, and the variation of the potential both along the strand length and across the strand cross section. The bidomain model i...

Cells in certain tissues, such as cardiac muscle, smooth muscle and liver, are known to form three-dimensional electrical syncytia (Eisenberg et al., 1979). In a syncytium, cells are electrically coupled to adjacent cells by means of protein structures known as gap junctions. These gap junctions provide intercellular pathways for the exchange of ions and other small molecules (Meşe et al., 2007...

Inhibition of aerobic metabolism leads to a major disruption of cardiac cell homeostasis. The purpose of the present study was twofold: 1) We determined the relative importance ofjunctional and nonjunctional membrane resistance (Rj and Rm, respectively) in the development of propagation failure during inhibition of aerobic metabolism in guinea pig ventricular cell pairs. 2) We used the patch-ac...

1. Initiation and propagation of action potentials evoked by extracellular synaptic stimulation was studied using simultaneous dual and triple patch pipette recordings from different locations on neocortical layer 5 pyramidal neurons in brain slices from 4-week-old rats (P26-30) at physiological temperatures. 2. Simultaneous cell-attached and whole-cell voltage recordings from the apical trunk ...

Cable theory and active equivalent circuits have been used to simulate the propagation of action potentials along a single nerve or muscle fiber by representing the cell as a unidimensional cable composed of isopotential segments. We extended this method to a two-dimensional sheet of cells which in many ways represents the atrium. Our method consisted of solving for the potential profile of a s...

Axons have traditionally been viewed as highly faithful transmitters of action potentials. Recently, however, experimental evidence has accumulated to support the idea that under some circumstances axonal propagation may fail. Cerebellar Purkinje neurons fire highfrequency simple spikes, as well as bursts of spikes in response to climbing fiber activation (the "complex spike"). Here we have vis...

The aim of this work was to demonstrate the correspondence between a macroscopic 3D computer model of electrophysiology (i.e., the Aliev-Panfilov model) parametrized with MR data and experimental characterization of action potential propagation in large porcine hearts, ex vivo, using optical methods (based on voltage-sensitive fluorescence). A secondary goal was to use one of these studies to d...

The influence of activation sequences on action potential configuration, especially in the repolarization phase, was examined in isolated canine ventricular muscles. Action potentials were recorded from the epicardial surface in the center of a preparation having nearly uniform fiber orientation (25 X 25 mm). Stimuli applied just adjacent to the recording site produced nearly centrifugal propag...

Action potential propagation links information processing in different regions of the dendritic tree. To examine the contribution of dendritic morphology to the efficacy of propagation, simulations were performed in detailed reconstructions of eight different neuronal types. With identical complements of voltage-gated channels, different dendritic morphologies exhibit distinct patterns of propa...