Kinetic properties of voltage gated Na channel (Nayak and Sikdar 2007)

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Accession:111967
Here we illustrate novel non-linear properties of voltage gated Na+ channel induced by sustained membrane depolarization. In cell-attached patch clamp recordings of rNav1.2 channels expressed in CHO cells, we found complex non-linear changes in the molecular kinetic properties, including channel dwell times and unitary conductance of single Na+ channels that were dependent on the extent of conditioning membrane depolarization. A “molecular memory” phenomenon arises at longer depolarization characterized by clusters of dwell time events and strong autocorrelation in dwell times. Hidden Markov Modeling (HMM) ... suggested a possible explanation to the memory phenomenon. See paper for more and details.
Reference:
1 . Nayak TK, Sikdar SK (2007) Time-dependent molecular memory in single voltage-gated sodium channel. J Membr Biol 219:19-36 [PubMed]
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Model Information (Click on a link to find other models with that property)
Model Type: Channel/Receptor;
Brain Region(s)/Organism:
Cell Type(s):
Channel(s): I Sodium;
Gap Junctions:
Receptor(s):
Gene(s):
Transmitter(s):
Simulation Environment: Yale HMM;
Model Concept(s): Ion Channel Kinetics; Epilepsy; Markov-type model;
Implementer(s): Nayak, Tapan Kumar [tapan at mbu.iisc.ernet.in];
Search NeuronDB for information about:  I Sodium;
States  
 0         8.84E-14       0.75
 0         8.84E-14       0.1
 0         8.84E-14       0.05
-1.23E-12  1.99E-13       0.0
 0         8.84E-14       0.1

Noise     
NoiseControl 1
StandardDeviation 2.05E-13
ARCoefficients	5.76E-001  -5.47E-001  4.31E-001  -2.02E-001

TransitionRate 	
-1000	1000     0     0    0 
 200   -1450    1000   0    250		
  0     200    -1650  1200  250 
  0     0       300  -700   400
  0     40      40    50   -130 

Simulator
NumberOfSweeps	  100
PointsInSweeps	 20000
SamplingInterval 0.00004