Abstract
Like the axolemma of the giant nerve fibre of the squid, the nodal membrane of frog myelinated nerve fibres after blocking transmembrane ionic currents exhibits asymmetrical displacement currents during and after hyperpolarizing and depolarizing voltage clamp pulses of equal size. The steady-state distribution of charges as a function of membrane potential is consistent with Boltzmanns law (midpoint potential minus 33.7 mV; saturation value 17200 charges/mum-2). The time course of the asymmetry current and the voltage dependence of its time constant are consistent with the notion that due to a sudden change in membrane potential the charges undergo a first order transition between two configurations. Size and voltage dependence of the time constant are similar to those of the activation of the sodium conductance assuming m-2h kinetics. The results suggest that the presence of ten times more sodium channels (5000/mum-2) in the node of Ranvier than in the squid giant axon with similar sodium conductance per channel (2-3 pS).
| Original language | English |
|---|---|
| Pages (from-to) | 483-492 |
| Number of pages | 10 |
| Journal | Philosophical transactions of the Royal Society of London. Series B: Biological sciences |
| Volume | 270 |
| Issue number | 908 |
| State | Published - Jun 10 1975 |
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ASJC Scopus subject areas
- Agricultural and Biological Sciences(all)
- Agricultural and Biological Sciences (miscellaneous)
Cite this
Gating currents in the node of Ranvier : voltage and time dependence. / Nonner, W.; Rojas, E.; Stämpfli, R.
In: Philosophical transactions of the Royal Society of London. Series B: Biological sciences, Vol. 270, No. 908, 10.06.1975, p. 483-492.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Gating currents in the node of Ranvier
T2 - voltage and time dependence.
AU - Nonner, W.
AU - Rojas, E.
AU - Stämpfli, R.
PY - 1975/6/10
Y1 - 1975/6/10
N2 - Like the axolemma of the giant nerve fibre of the squid, the nodal membrane of frog myelinated nerve fibres after blocking transmembrane ionic currents exhibits asymmetrical displacement currents during and after hyperpolarizing and depolarizing voltage clamp pulses of equal size. The steady-state distribution of charges as a function of membrane potential is consistent with Boltzmanns law (midpoint potential minus 33.7 mV; saturation value 17200 charges/mum-2). The time course of the asymmetry current and the voltage dependence of its time constant are consistent with the notion that due to a sudden change in membrane potential the charges undergo a first order transition between two configurations. Size and voltage dependence of the time constant are similar to those of the activation of the sodium conductance assuming m-2h kinetics. The results suggest that the presence of ten times more sodium channels (5000/mum-2) in the node of Ranvier than in the squid giant axon with similar sodium conductance per channel (2-3 pS).
AB - Like the axolemma of the giant nerve fibre of the squid, the nodal membrane of frog myelinated nerve fibres after blocking transmembrane ionic currents exhibits asymmetrical displacement currents during and after hyperpolarizing and depolarizing voltage clamp pulses of equal size. The steady-state distribution of charges as a function of membrane potential is consistent with Boltzmanns law (midpoint potential minus 33.7 mV; saturation value 17200 charges/mum-2). The time course of the asymmetry current and the voltage dependence of its time constant are consistent with the notion that due to a sudden change in membrane potential the charges undergo a first order transition between two configurations. Size and voltage dependence of the time constant are similar to those of the activation of the sodium conductance assuming m-2h kinetics. The results suggest that the presence of ten times more sodium channels (5000/mum-2) in the node of Ranvier than in the squid giant axon with similar sodium conductance per channel (2-3 pS).
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M3 - Article
C2 - 238243
AN - SCOPUS:0016848153
VL - 270
SP - 483
EP - 492
JO - Proceedings of the Royal Society B: Biological Sciences
JF - Proceedings of the Royal Society B: Biological Sciences
SN - 0800-4622
IS - 908
ER -