What question did this study set out to answer?

To determine the relationship between intracellular spike amplitude and external calcium ion concentration and investigate its interactions with external sodium and potassium in lobster giant axons.

January 1, 1960The Journal of General PhysiologyOpen Access

Interactions of Calcium with Sodium and Potassium in Membrane Potentials of the Lobster Giant Axon

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Authors

WAWilliam J. AdelmanUniversity of Vermont JDJohn Call DaltonNational Institutes of Health

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Implication

Experimental study demonstrates synergistic action potential reduction during concurrent calcium and sodium or potassium depletion in lobster giant axons, suggesting strong multi-ion interactions.

Key Points

To determine the relationship between intracellular spike amplitude and external calcium ion concentration and investigate its interactions with external sodium and potassium in lobster giant axons.
Measured intracellular action potentials in isolated lobster giant axons under varying external ionic environments.
Manipulated extracellular calcium concentrations across a range of 2.5 to 50 mM in combination with normal or reduced (50% reduction) sodium, as well as elevated potassium.
Simultaneous reduction of external calcium and sodium produced a decline in action potential amplitude significantly greater than the additive sum of individual ion reductions.
Spike height scaled proportionally with the logarithm of calcium concentration (2.5 to 50 mM), with a 50% reduction in sodium increasing the linear slope by approximately 5-fold relative to normal sodium.
Concurrently lowering calcium and increasing potassium caused greater spike amplitude attenuation than the arithmetic sum of low calcium and high potassium applied individually.

Cite This Study

Adelman et al. (1960) studied this question.

synapsesocial.com/papers/6a0f084eb7cc3b883f22ff2d https://doi.org/10.1085/jgp.43.3.609

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Implication

Experimental study demonstrates synergistic action potential reduction during concurrent calcium and sodium or potassium depletion in lobster giant axons, suggesting strong multi-ion interactions.

Interactions of Calcium with Sodium and Potassium in Membrane Potentials of the Lobster Giant Axon

Discussion

Member takes

Implication

Key Points

Cite This Study

Interactions of Calcium with Sodium and Potassium in Membrane Potentials of the Lobster Giant Axon

Discussion

Member takes

Implication

Key Points

Cite This Study

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