scholarly journals Critical behavior in the artificial axon

2021 ◽  
Author(s):  
Ziqi Pi ◽  
Giovanni Zocchi
Keyword(s):  
Ion Channel ◽  
Critical Behavior ◽  
Delay Time ◽  
Action Potentials ◽  
Scaling Exponent ◽  
Saddle Node Bifurcation ◽  
Channel Dynamics ◽  
A Cell ◽  
Universal Properties ◽  
Fast Ion

Abstract The Artificial Axon is a unique synthetic system, based on biomolecular components, which supports action potentials. Here we examine, experimentally and theoretically, the properties of the threshold for firing in this system. As in real neurons, this threshold corresponds to the critical point of a saddle-node bifurcation. We measure the delay time for firing as a function of the distance to threshold, recovering the expected scaling exponent of −1/2. We introduce a minimal model of the Morris-Lecar type, validate it on the experiments, and use it to extend analytical results obtained in the limit of ”fast” ion channel dynamics. In particular, we discuss the dependence of the firing threshold on the number of channels. The Artificial Axon is a simplified system, an Ur-neuron, relying on only one ion channel species for functioning. Nonetheless, universal properties such as the action potential behavior near threshold are the same as in real neurons. Thus we may think of the Artificial Axon as a cell-free breadboard for electrophysiology research.

A cell-based impedance assay for monitoring transient receptor potential (TRP) ion channel activity

2011 ◽  
Vol 26 (5) ◽  
pp. 2376-2382 ◽  
Author(s):  
Oliver Pänke ◽  
Winnie Weigel ◽  
Sabine Schmidt ◽  
Anja Steude ◽  
Andrea A. Robitzki
Keyword(s):  
Ion Channel ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Channel Activity ◽  
A Cell ◽  
Transient Receptor ◽  
Trp Ion Channel

scholarly journals Stochastic models and simulation of ion channel dynamics

2010 ◽  
Vol 1 (1) ◽  
pp. 1587-1596 ◽  
Author(s):  
C.E. Dangerfield ◽  
D. Kay ◽  
K. Burrage
Keyword(s):  
Ion Channel ◽  
Stochastic Models ◽  
Channel Dynamics

Nanoscale metal oxide-based composite membranes with fast ion channel for Li metal protection

Ionics ◽  
2021 ◽  
Author(s):  
Yaxin Zhang ◽  
Yitao He ◽  
Chunyu Jin ◽  
Yaohui Zhang ◽  
Zhihong Wang ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Ion Channel ◽  
Composite Membranes ◽  
Fast Ion ◽  
Metal Protection

scholarly journals Cardiac Transmembrane Ion Channels and Action Potentials: Cellular Physiology and Arrhythmogenic Behavior

2020 ◽  
Author(s):  
András Varró ◽  
Jakub Tomek ◽  
Norbert Nagy ◽  
Laszlo Virag ◽  
Elisa Passini ◽  
...  
Keyword(s):  
Ion Channel ◽  
Action Potentials ◽  
Cardiac Electrophysiology ◽  
Current Knowledge ◽  
Animal Experiments ◽  
Cardiac Cells ◽  
Cellular Mechanisms ◽  
Electrophysiological Properties ◽  
Channel Expression ◽  
Ionic Mechanisms

Cardiac arrhythmias are among the leading causes of mortality. They often arise from alterations in the electrophysiological properties of cardiac cells, and their underlying ionic mechanisms. It is therefore critical to further unravel the patho-physiology of the ionic basis of human cardiac electrophysiology in health and disease. In the first part of this review, current knowledge on the differences in ion channel expression and properties of the ionic processes that determine the morphology and properties of cardiac action potentials and calcium dynamics from cardiomyocytes in different regions of the heart are described. Then the cellular mechanisms promoting arrhythmias in congenital or acquired conditions of ion channel function (electrical remodelling) are discussed. The focus is human relevant findings obtained with clinical, experimental and computational studies, given that interspecies differences make the extrapolation from animal experiments to the human clinical settings difficult. Deepening the understanding of the diverse patholophysiology of human cellular electrophysiology will help developing novel and effective antiarrhythmic strategies for specific subpopulations and disease conditions.

scholarly journals NEURAL EXCITABILITY, SPIKING AND BURSTING

2000 ◽  
Vol 10 (06) ◽  
pp. 1171-1266 ◽  
Author(s):  
EUGENE M. IZHIKEVICH
Keyword(s):  
Action Potentials ◽  
Bifurcation Theory ◽  
Low Frequency ◽  
Input Frequency ◽  
Frequency Range ◽  
Saddle Node Bifurcation ◽  
Neural Excitability ◽  
Rest State ◽  
Computational Properties

Bifurcation mechanisms involved in the generation of action potentials (spikes) by neurons are reviewed here. We show how the type of bifurcation determines the neuro-computational properties of the cells. For example, when the rest state is near a saddle-node bifurcation, the cell can fire all-or-none spikes with an arbitrary low frequency, it has a well-defined threshold manifold, and it acts as an integrator; i.e. the higher the frequency of incoming pulses, the sooner it fires. In contrast, when the rest state is near an Andronov–Hopf bifurcation, the cell fires in a certain frequency range, its spikes are not all-or-none, it does not have a well-defined threshold manifold, it can fire in response to an inhibitory pulse, and it acts as a resonator; i.e. it responds preferentially to a certain (resonant) frequency of the input. Increasing the input frequency may actually delay or terminate its firing. We also describe the phenomenon of neural bursting, and we use geometric bifurcation theory to extend the existing classification of bursters, including many new types. We discuss how the type of burster defines its neuro-computational properties, and we show that different bursters can interact, synchronize and process information differently.

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