The foundational explanation of action potential transmission comes from Hodgkin & Huxley (1952)1, who used the voltage-clamp technique on the squid giant axon to produce a quantitative description of the process1
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1
A quantitative description of membrane current and its application to conduction and excitation in nerveAlan L. Hodgkin, Andrew F. Huxley1952The Journal of Physiology
The action potential is driven by voltage-dependent ionic currents across the cell membrane1. The membrane current can be separated into two independent components1
:
Sodium (Na⁺) conductance — the upstroke: When the membrane is depolarized above a threshold, there is a rapid, transient rise in sodium conductance, which drives the upstroke of the action potential
1
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Potassium (K⁺) conductance — repolarization: This is followed by a slower, sustained rise in potassium conductance, along with inactivation of the sodium channels, which together repolarize the membrane back toward its resting state
1
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Key Characteristics
The process exhibits an all-or-none character — meaning once the threshold is crossed, the full action potential fires1. The Hodgkin–Huxley model, a set of equations describing how these conductances vary with membrane voltage and time, was shown to reproduce the form, amplitude, threshold, and conduction velocity of the propagated nerve impulse1
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⚠️ Scope note: The above reflects the findings of a single landmark paper. While Hodgkin & Huxley (1952)
1
is the foundational source on this mechanism, I cannot characterize this as broader field consensus from the retrieved evidence alone, as only one paper was provided.