Alteration in Sodium Channel Gate Kinetics of the Hodgkin-Huxley Equations Applied to an Electric Field Model for Interaction Between Excitable Cells

1981 ◽  
Vol BME-28 (9) ◽  
pp. 655-661 ◽  
Author(s):  
James E. Mann ◽  
Nick Sperelakis ◽  
James A. Ruffner
Keyword(s):  
Electric Field ◽  
Sodium Channel ◽  
Field Model ◽  
Excitable Cells ◽  
Channel Gate ◽  
Kinetics Of

scholarly journals Kinetic Analysis of Block of Open Sodium Channels by a Peptide Containing the Isoleucine, Phenylalanine, and Methionine (IFM) Motif from the Inactivation Gate

1998 ◽  
Vol 111 (1) ◽  
pp. 75-82 ◽  
Author(s):  
Galen Eaholtz ◽  
William N. Zagotta ◽  
William A. Catterall
Keyword(s):  
Electric Field ◽  
Sodium Channel ◽  
Kinetic Analysis ◽  
Sodium Channels ◽  
Rate Constant ◽  
Voltage Dependence ◽  
Bimolecular Reaction ◽  
Voltage Dependent ◽  
Kinetics Of ◽  
The Brain

We analyzed the kinetics of interaction between the peptide KIFMK, containing the isoleucine, phen-ylalanine, and methionine (IFM) motif from the inactivation gate, and the brain type IIA sodium channels with a mutation that disrupts inactivation (F1489Q). The on-rate constant was concentration dependent, consistent with a bimolecular reaction with open sodium channels, while the off rates were unaffected by changes in the KIFMK concentration. The apparent Kd was ∼33 μM at 0 mV. The on rates were voltage dependent, supporting the hypothesis that one or both of the charges in KIFMK enter the membrane electric field. The voltage dependence of block was consistent with the equivalent movement of ∼0.6 electronic charges across the membrane. In contrast, the off rates were voltage independent. The results are consistent with the hypothesis that the KIFMK peptide enters the pore of the open sodium channel from the intracellular side and blocks it.

scholarly journals Electrodiffusion model of synaptic potentials in dendritic spines

2018 ◽  
Author(s):  
Thibault Lagache ◽  
Krishna Jayant ◽  
Rafael Yuste
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Dendritic Spines ◽  
Ionic Currents ◽  
Ion Concentration ◽  
Excitable Cells ◽  
Main Site ◽  
Synaptic Potentials ◽  
Concentration Changes ◽  
Kinetics Of

ABSTRACTWhen modeling electric current flow in neurons and excitable cells, traditional cable theory ignores electrodiffusion (i.e. the interaction between electric fields and ionic diffusion) as it assumes that concentration changes associated with ionic currents are negligible. This assumption, while true for large neuronal compartments, fails when applied to femto-liter size compartments such as dendritic spines - small protrusions that form the main site of synaptic inputs in the brain. Here, we use the Poisson (P) and Nernst-Planck (NP) equations, which relate electric field to charge and couple Fick’s law of diffusion to the electric field, to model ion concentration dynamics in dendritic spines. We use experimentally measured voltage transients from spines with nanoelectrodes to explore these dynamics with realistic parameters. We find that (i) passive diffusion and electrodiffusion jointly affect the kinetics of spine excitatory post-synaptic potentials (EPSPs); (ii) spine geometry plays a key role in shaping EPSPs; and, (iii) the spine-neck resistance dynamically decreases during EPSPs, leading to short-term synaptic facilitation. Our formulation can be easily adopted to model ionic biophysics in a variety of nanoscale bio-compartments.

The sodium channel  -subunit SCN3b modulates the kinetics of SCN5a and is expressed heterogeneously in sheep heart

2001 ◽  
Vol 537 (3) ◽  
pp. 693-700 ◽  
Author(s):  
A. I Fahmi ◽  
M. Patel ◽  
E. B Stevens ◽  
A. L Fowden ◽  
J. E. John ◽  
...  
Keyword(s):  
Sodium Channel ◽  
Kinetics Of

Photoluminescence kinetics of type II GaAs/AlAs superlattices under the influence of an electric field

2005 ◽  
Author(s):  
D. V. Gulyaev ◽  
A. K. Bakarov ◽  
A. V. Tsarev ◽  
K. S. Zhuravlev
Keyword(s):  
Electric Field ◽  
Type Ii ◽  
Kinetics Of
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