Riluzole inhibits the persistent sodium current in mammalian CNS neurons

Eur J Neurosci. 2000 Oct;12(10):3567-74. doi: 10.1046/j.1460-9568.2000.00242.x.


The effects of 0.1-100 microM riluzole, a neuroprotective agent with anticonvulsant properties, were studied on neurons from rat brain cortex. Patch-clamp whole-cell recordings in voltage-clamp mode were performed on thin slices to examine the effects of the drug on a noninactivating (persistent) Na+ current (INa,p). INa,p was selected because it enhances neuronal excitability near firing threshold, which makes it a potential target for anticonvulsant drugs. When added to the external solution, riluzole dose-dependently inhibited INa,p up to a complete blocking of the current (EC50 2 microM), showing a significant effect at therapeutic drug concentrations. A comparative dose-effect study was carried out in the same cells for the other main known action of riluzole, the inhibitory effect on the fast transient sodium current. This effect was confirmed in our experiments, but we found that it was achieved at levels much higher than putative therapeutic concentrations. Only the effect on INa,p, and not that on fast sodium current, can account for the reduction in neuronal excitability observed in cortical neurons following riluzole treatment at therapeutic concentrations, and this might represent a novel mechanism accounting for the anticonvulsant and neuroprotective properties of riluzole.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / drug effects
  • Action Potentials / physiology
  • Animals
  • Anticonvulsants / pharmacology
  • Cell Membrane / drug effects
  • Cell Membrane / metabolism
  • Cerebral Cortex / cytology
  • Cerebral Cortex / drug effects*
  • Cerebral Cortex / metabolism
  • Dose-Response Relationship, Drug
  • Neurons / cytology
  • Neurons / drug effects*
  • Neurons / metabolism
  • Neuroprotective Agents / pharmacology
  • Patch-Clamp Techniques / statistics & numerical data
  • Rats
  • Rats, Wistar
  • Riluzole / pharmacology*
  • Sodium Channels / drug effects*
  • Sodium Channels / metabolism


  • Anticonvulsants
  • Neuroprotective Agents
  • Sodium Channels
  • Riluzole

Grant support