Contributions of the sodium pump and ionic gradients to the membrane potential of a molluscan neurone
A. L. F. Gorman,M. F. Marmor +1 more
TLDR
The membrane potential of the gastro‐oesophageal giant neurone of the marine mollusc, Anisodoris nobilis, was examined during changes of temperature and of the ionic medium.Abstract:
1. The membrane potential of the gastro-oesophageal giant neurone of the marine mollusc, Anisodoris nobilis, was examined during changes of temperature and of the ionic medium.2. The response of the membrane potential to rapid changes in the external K concentration was prompt, stable, and reversible up to 200 mM-K, and was independent of the external Cl concentration.3. Warming the cell produced a prompt hyperpolarization that was approximately 10 times greater than predicted by the Nernst or constant field equations. Electrogenic activity of the Na-K exchange pump was shown to be responsible for this effect.4. At temperatures below 5 degrees C, the relationship between the membrane potential and the external K concentration could be predicted by a constant field equation.5. At temperatures above 5 degrees C, the membrane potential could not be predicted by the constant field equation except after inhibition of the electrogenic Na pump with ouabain or the reduction of internal Na.6. Inhibition of the electrogenic Na pump by low external K concentrations was dependent upon the external Na concentration.7. It is concluded that the membrane potential is the sum of ionic and metabolic components, and that the behaviour of the ionic component can be predicted by a constant field type equation.read more
Citations
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The resting potential of cockroach muscle membrane
TL;DR: Evidence is presented that Em of cockroach muscle has two components, an active component generating about 18 mV and an ionic electrode, dominated by K+, which is responsible for about 42 mV, and one of its functions is the outward transport of K+.
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On the pump-induced cell volume changes
TL;DR: The correlation between electrogenic Na-K-pump activity and completely isolated nerve cell volume changes was studied and intracellular Na ions concentration was reduced without essentially changing K ion concentration with increasing of external potassium from 0–45 mM.
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Neurochemical transmission and the sodium-pump
TL;DR: Current carried by the sodium-pump Sodmm gradient created by the sodmm-p Pump, sodmm -calcmm exchange SodlUm-DUmD and neurotransmltter release 5.7.
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Microelectrode studies on Malpighian tubule cells of Locusta migratoria: Effects of external ions and inhibitors
P. Baldrick,D. Hyde,J.H. Anstee +2 more
TL;DR: Basal and apical membrane potentials were recorded from Malpighian tubules of Locusta using intracellular microelectrodes and data from ion substitution experiments suggest that Cl − entry across the basal membrane is K + -dependent and the responses to Na + -free and Cl − -free salines bring into question the role of Na + in the entry of chloride across thebasal membrane by co-transport.
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Calcium in phase control of theBulla circadian pacemaker
Sat Bir S. Khalsa,Gene D. Block +1 more
TL;DR: The hypothesis that calcium fluxes play a pivotal role in the entrainment pathway of the circadian pacemaker is discussed, where a transmembrane calcium flux is known to be essential for both light and depolarization-induced phase shifting.
References
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Journal ArticleDOI
The effect of sodium ions on the electrical activity of the giant axon of the squid
A. L. Hodgkin,B. Katz +1 more
Journal ArticleDOI
Potential, impedance, and rectification in membranes
TL;DR: A theoretical picture has been presented based on the use of the general kinetic equations for ion motion under the influence of diffusion and electrical forces and on a consideration of possible membrane structures that shows qualitative agreement with the rectification properties and very good agreementwith the membrane potential data.
Journal ArticleDOI
The influence of potassium and chloride ions on the membrane potential of single muscle fibres.
A. L. Hodgkin,P. Horowicz +1 more
TL;DR: The most widely accepted theory of the restirng potential of muscle is that the electrical potential difference between the inside and outside of a muscle fibre arises from the concentration gradients of the potassium and chloride ions.
Journal ArticleDOI
The influence of calcium on sodium efflux in squid axons.
TL;DR: This work has shown that the sodium efflux from the axons of Loligo forbesi increases when external sodium is replaced by lithium.
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