Wireless Force-Inducing Neuronal Stimulation Mediated by High Magnetic Moment Microdiscs

Area of Science:

• Neuroscience
• Biomaterials Science
• Biophysics

Background:

• Noninvasive manipulation of cell signaling is crucial for neuroscience research and therapies.
• Current neuromodulation techniques face limitations in cell-type specificity and magnetic field strength.

Purpose of the Study:

• To describe a novel method for wireless, force-induced stimulation of primary neuronal circuits.
• To utilize magnetic microdiscs (MMDs) as transducers for converting alternating magnetic fields (AMFs) into mechanical forces for neuronal activation.

Main Methods:

• Fabrication of biocompatible MMDs using cost-effective top-down lithography.
• Application of low-intensity, low-frequency AMFs to MMDs in contact with primary rat neuronal cultures.
• Confirmation of mechanotransduction via inhibition with Gadolinium (Gd³⁺).

Main Results:

• MMDs effectively translated AMFs into mechanical forces, activating mechanosensitive ion channels.
• Significant neuronal activation observed: ≈50% of hippocampal and ≈90% of cortical neurons.
• No cytotoxic effects were detected in neuronal cultures.
• High efficiency and long-lasting neuronal stimulations were achieved.

Conclusions:

• This MMD-based technology offers cell-type specificity and utilizes weak magnetic fields, addressing key limitations in neuromodulation.
• Represents a significant advancement in magneto-mechanical control of neural activity.
• Paves the way for improved noninvasive neuromodulation therapies and clinical equipment design.