Exciting the brain through micromagnetic stimulation

White matter fibers in the brain can be selectively stimulated and excited by micromagnetic stimulation (μMS), a new approach to neuronal stimulation. The μMS system proposed by Jeong et al. deposits figure 8 coils deep into the brain, inducing microscopic but relatively large currents when a magnetic field is applied. This process has similar therapeutic effects to conventional electrical stimulation but provides greater focal neuron activation and is not impeded by charge build up in electrodes.

“One of the significant limitations of current neuromodulation medical devices is their limited compatibility with MRI,” said author Giorgio Bonmassar. “μMS probes can be insulated entirely from the brain tissue, significantly reducing the problem of excessive power deposition into the brain during MRI.”

Existing neuromodulation devices, such as vagus nerve stimulators and spinal cord stimulators, are used to treat medical conditions but require invasive procedures.

“The μMS technology we propose is contactless, so biocompatible materials will allow implantation with minimal or no reaction,” said Bonmassar. “μMS could overcome many invasive devices that require electrodes to be in direct contact with the excitable tissue.”

Deep brain manipulation technology utilizing μMS will allow the investigation of neuron and neural network function in the peripheral and central nervous systems, greatly aiding future neuroscience research. μMS could be used in conjunction with optogenetic studies to observe neuronal activity.

“The flexible films we have used could wrap optical fibers for optogenetic stimulation, offering the ability to stimulate genetically modified neurons and significantly benefiting basic neuroscience research,” said Bonmassar.

Source: “Planar figure-8 coils for ultra-focal and directional micromagnetic brain stimulation,” by Hongbae Jeong, Jiangdong Deng, and Giorgio Bonmassar. Journal of Vacuum Science and Technology B (2021). The article can be accessed at https://doi.org/10.1116/6.0001281 .

This paper is part of the 64th International Conference on Electron, Ion, And Photon Beam Technology and Nanofabrication Collection, learn more here .