Different effects of blocked potassium channels on action potentials, accommodation, adaptation and anode break excitation in human motor and sensory myelinated nerve fibres: computer simulations

2000 ◽  
Vol 83 (2) ◽  
pp. 161-167 ◽  
Author(s):  
D. I. Stephanova ◽  
K. Mileva
1982 ◽  
Vol 215 (1200) ◽  
pp. 273-287 ◽  

A study has been made of how the normal complementary distribution of sodium and potassium channels in mammalian myelinated nerve fibres (all the sodium channels being in the node with all the potassium channels in the internode) is altered in regenerating and in developing rabbit sciatic nerves. In regenerating nerve fibres, where a marked increase in the number of nodes per unit length occurs, there is a corresponding increase in the sodium channel content (determined from the maximum saturable binding of labelled saxitoxin), consistent with the idea that the number of sodium channels per node remains roughly constant. The use of 4-aminopyridine, which by blocking potassium channels prolongs the action potential, has shown that both in regenerating nerve fibres and in developing nerve fibres potassium currents contribute to the mammalian action potential. In both cases, with the passage of time, the sensitivity to 4-aminopyridine progressively decreases.


1983 ◽  
Vol 36 (1) ◽  
pp. 49-53 ◽  
Author(s):  
Rolf P. Spielmann ◽  
Jürgen R. Schwarz ◽  
Burkhart Bromm

1984 ◽  
Vol 220 (1221) ◽  
pp. 415-422 ◽  

A theoretical analysis of the passive electrical properties of normal myelinated nerve suggests that the function of the voltage-dependent potassium channels in the internodal axolemma under the myelin sheath is to permit the generation of an internodal resting potential. Calculation shows that if this internodal potential were not present, the nodal potential would be reduced (by electrotonic short-circuiting) thus impairing the security of conduction. This impairment is particularly pronounced with smaller diameter fibres.


2008 ◽  
Vol 29 (6) ◽  
pp. 1100-1106 ◽  
Author(s):  
Alexia Kagiava ◽  
Anastasia Tsingotjidou ◽  
Christos Emmanouilides ◽  
George Theophilidis

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