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Optogenetic Activation of Afferent Pathways in Brain Slices and Modulation of Responses by Volatile Anesthetics
Published on: July 23, 2020
Sodium channels as targets for volatile anesthetics
Karl F Herold1, Hugh C Hemmings
1Department of Anesthesiology, Weill Cornell Medical College New York, NY, USA.
Frontiers in Pharmacology
|April 6, 2012
Summary
Inhaled anesthetics inhibit sodium (Na+) channels, reducing neurotransmitter release and contributing to anesthesia effects like unconsciousness and immobility. This mechanism is key to understanding how these drugs work.
Area of Science:
- Neuroscience
- Anesthesiology
- Molecular Pharmacology
Background:
- The precise molecular targets of inhaled anesthetics remain unclear despite their widespread clinical use.
- Evidence suggests these anesthetics affect membrane proteins, particularly ion channels in excitable cells.
Purpose of the Study:
- To investigate the role of sodium (Na+) channels as targets for volatile anesthetics.
- To elucidate how Na+ channel inhibition contributes to the central nervous system effects of inhaled anesthetics.
Main Methods:
- Examined effects of volatile anesthetics on Na+ currents in neuronal preparations and heterologous expression systems.
- Utilized electrophysiological techniques to assess Na+ current inhibition and inactivation kinetics.
- Conducted animal studies involving intrathecal administration of Na+ channel modulators.
Main Results:
- Volatile anesthetics inhibit presynaptic Na+ currents (I(Na)) at clinical concentrations.
- Anesthetics shift the voltage dependence of Na+ channel inactivation to more negative potentials, slowing recovery.
- Reduced neurotransmitter release, particularly glutamate, was observed, correlating with anesthetic potency in animal models.
Conclusions:
- Inhibition of presynaptic Na+ channels is a significant mechanism underlying the central nervous system depressant effects of inhaled anesthetics.
- These effects on Na+ channels contribute to amnesia, unconsciousness, and immobility.
- Targeting Na+ channels offers a potential avenue for understanding and refining anesthetic actions.
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