Static Magnetic Field Stimulation Enhances Shunting Inhibition via a SLC26 Family Cl^- Channel, Inducing Intrinsic...

Area of Science:

• Neuroscience
• Biophysics

Background:

• Magnetic fields are increasingly used for brain examination and treating dysfunctions.
• Transcranial static magnetic field stimulation (tSMS) is a novel noninvasive technique to modify brain functions.
• The neurophysiological mechanisms of tSMS-induced plasticity are not fully understood.

Purpose of the Study:

• To investigate the neurophysiological mechanisms underlying tSMS-induced neuronal plasticity.
• To determine how static magnetic fields (SMF) affect neuronal electrical properties.

Main Methods:

• Acute motor cortical slice preparation from male C57BL/6N mice.
• Whole-cell voltage-clamp recordings to assess neuronal excitability and ion channel activity.
• Application of static magnetic fields (SMF) mimicking human tSMS parameters.
• Pharmacological assessment using DIDS, GlyH-101, and NPPB to identify involved ion channels.

Main Results:

• SMF exposure decreased neuronal excitability and induced transient neuronal swelling in mouse pyramidal neurons.
• SMF effects were blocked by DIDS and GlyH-101, implicating SLC26A11 chloride channels.
• Enhanced GlyH-101-sensitive chloride current was observed after SMF, leading to shunting inhibition and reduced action potential firing.

Conclusions:

• This study provides the first neurophysiological evidence for the inhibitory effect of tSMS on neuronal activity.
• tSMS alters neuronal intrinsic electrical properties by modulating chloride channel activity.
• These findings advance the mechanistic understanding of noninvasive neuromodulation techniques like tSMS.