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Updated: Jul 16, 2026

Contribution of the Na+/K+ Pump to Rhythmic Bursting, Explored with Modeling and Dynamic Clamp Analyses
Published on: May 9, 2021
Persistent sodium current and its role in epilepsy
1Section of Pediatric Neurology, Department of Neurology, University of Wisconsin Madison, Wisconsin, USA. stafstrom@neurology.wisc.edu
Abstract:
Sodium currents are essential for the initiation and propagation of neuronal firing. Alterations of sodium currents can lead to abnormal neuronal activity, such as occurs in epilepsy. The transient voltage-gated sodium current mediates the upstroke of the action potential. A small fraction of sodium current, termed the persistent sodium current (I(NaP)), fails to inactivate significantly, even with prolonged depolarization. I(NaP) is activated in the subthreshold voltage range and is capable of amplifying a neuron's response to synaptic input and enhancing its repetitive firing capability. A burgeoning literature is documenting mutations in sodium channels that underlie human disease, including epilepsy. Some of these mutations lead to altered neuronal excitability by increasing I(NaP). This review focuses on the pathophysiological effects of I(NaP) in epilepsy.
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